Substituted quinoxaline dna-pk inhibitors

ABSTRACT

The present invention relates to compounds useful as inhibitors of DNA-PK. The invention also provides pharmaceutically acceptable compositions comprising said compounds and methods of using the compositions in the treatment of various disease, conditions, or disorders.

This application claims the benefit to U.S. Provisional Application No.61/777,816, filed on Mar. 12, 2013, the entire content of which isincorporated herein by reference.

TECHNICAL FIELD OF THE INVENTION

The present invention relates to compounds useful as inhibitors ofDNA-dependent protein kinase (DNA-PK). The invention also providespharmaceutically acceptable compositions comprising the compounds of theinvention and methods of using the compositions in the treatment ofcancer.

BACKGROUND OF THE INVENTION

Ionizing radiation (IR) induces a variety of DNA damage of which doublestrand breaks (DSBs) are the most cytotoxic. These DSBs can lead to celldeath via apoptosis and/or mitotic catastrophe if not rapidly andcompletely repaired. In addition to IR, certain chemotherapeutic agentsincluding topoisomerase II inhibitors, bleomycin, and doxorubicin alsocause DSBs. These DNA lesions trigger a complex set of signals throughthe DNA damage response network that function to repair the damaged DNAand maintain cell viability and genomic stability. In mammalian cells,the predominant repair pathway for DSBs is the Non-Homologous EndJoining Pathway (NHEJ). This pathway functions regardless of the phaseof the cell cycle and does not require a template to re-ligate thebroken DNA ends. NHEJ requires coordination of many proteins andsignaling pathways. The core NHEJ machinery consists of the Ku70/80heterodimer and the catalytic subunit of DNA-dependent protein kinase(DNA-PKcs), which together comprise the active DNA-PK enzyme complex.DNA-PKcs is a member of the phosphatidylinositol 3-kinase-related kinase(PIKK) family of serine/threonine protein kinases that also includesataxia telangiectasia mutated (ATM), ataxia telangiectasia andRad3-related (ATR), mTOR, and four PI3K isoforms. However, whileDNA-PKcs is in the same protein kinase family as ATM and ATR, theselatter kinases function to repair DNA damage through the HomologousRecombination (HR) pathway and are restricted to the S and G₂ phases ofthe cell cycle. While ATM is also recruited to sites of DSBs, ATR isrecruited to sites of single stranded DNA breaks.

NHEJ is thought to proceed through three key steps: recognition of theDSBs, DNA processing to remove non-ligatable ends or other forms ofdamage at the termini, and finally ligation of the DNA ends. Recognitionof the DSB is carried out by binding of the Ku heterodimer to the raggedDNA ends followed by recruitment of two molecules of DNA-PKcs toadjacent sides of the DSB; this serves to protect the broken terminiuntil additional processing enzymes are recruited. Recent data supportsthe hypothesis that DNA-PKcs phosphorylates the processing enzyme,Artemis, as well as itself to prepare the DNA ends for additionalprocessing. In some cases DNA polymerase may be required to synthesizenew ends prior to the ligation step. The auto-phosphorylation ofDNA-PKcs is believed to induce a conformational change that opens thecentral DNA binding cavity, releases DNA-PKcs from DNA, and facilitatesthe ultimate religation of the DNA ends.

It has been known for some time that DNA-PK^(−/−) mice arehypersensitive to the effects of IR and that some non-selective smallmolecule inhibitors of DNA-PKcs can radiosensitize a variety of tumorcell types across a broad set of genetic backgrounds. While it isexpected that inhibition of DNA-PK will radiosensitize normal cells tosome extent, this has been observed to a lesser degree than with tumorcells likely due to the fact that tumor cells possess higher basallevels of endogenous replication stress and DNA damage (oncogene-inducedreplication stress) and DNA repair mechanisms are less efficient intumor cells. Most importantly, an improved therapeutic window withgreater sparing of normal tissue will be imparted from the combinationof a DNA-PK inhibitor with recent advances in precision delivery offocused IR, including image-guide RT (IGRT) and intensity-modulated RT(IMRT).

Inhibition of DNA-PK activity induces effects in both cycling andnon-cycling cells. This is highly significant since the majority ofcells in a solid tumor are not actively replicating at any given moment,which limits the efficacy of many agents targeting the cell cycle.Equally intriguing are recent reports that suggest a strong connectionbetween inhibition of the NHEJ pathway and the ability to killtraditionally radioresistant cancer stem cells (CSCs). It has been shownin some tumor cells that DSBs in dormant CSCs predominantly activate DNArepair through the NHEJ pathway; it is believed that CSCs are usually inthe quiescent phase of the cell cycle. This may explain why half ofcancer patients may experience local or distant tumor relapse despitetreatment as current strategies are not able to effectively target CSCs.A DNA-PK inhibitor may have the ability to sensitize these potentialmetastatic progenitor cells to the effects of IR and select DSB-inducingchemotherapeutic agents.

Given the involvement of DNA-PK in DNA repair processes, an applicationof specific DNA-PK inhibitory drugs would be to act as agents that willenhance the efficacy of both cancer chemotherapy and radiotherapy.Accordingly, it would be desirable to develop compounds useful asinhibitors of DNA-PK.

SUMMARY OF THE INVENTION

It has been found that compounds of this invention, and pharmaceuticallyacceptable compositions thereof, are effective as inhibitors of DNA-PK.Accordingly, the invention features compounds having the generalformula:

or a pharmaceutically acceptable salt thereof, where each of R¹, R², X,Ring A, Ring B and Ring C is as defined elsewhere herein.

The invention also provides pharmaceutical compositions that include acompound of formula I and a pharmaceutically acceptable carrier,adjuvant, or vehicle. These compounds and pharmaceutical compositionsare useful for treating or lessening the severity of cancer.

The compounds and compositions provided by this invention are alsouseful for the study of DNA-PK in biological and pathological phenomena;the study of intracellular signal transduction pathways mediated by suchkinases; and the comparative evaluation of new kinase inhibitors.

DETAILED DESCRIPTION OF THE INVENTION Definitions and GeneralTerminology

As used herein, the following definitions shall apply unless otherwiseindicated. For purposes of this invention, the chemical elements areidentified in accordance with the Periodic Table of the Elements, CASversion, and the Handbook of Chemistry and Physics, 75^(th) Ed. 1994.Additionally, general principles of organic chemistry are described in“Organic Chemistry,” Thomas Sorrell, University Science Books,Sausalito: 1999, and “March's Advanced Organic Chemistry,” 5^(th) Ed.,Smith, M. B. and March, J., eds. John Wiley & Sons, New York: 2001, theentire contents of which are hereby incorporated by reference.

As described herein, compounds of the invention may optionally besubstituted with one or more substituents, such as are illustratedgenerally above, or as exemplified by particular classes, subclasses,and species of the invention. It will be appreciated that the phrase“optionally substituted” is used interchangeably with the phrase“substituted or unsubstituted.” In general, the term “substituted,”whether preceded by the term “optionally” or not, refers to thereplacement of one or more hydrogen radicals in a given structure withthe radical of a specified substituent. Unless otherwise indicated, anoptionally substituted group may have a substituent at eachsubstitutable position of the group. When more than one position in agiven structure can be substituted with more than one substituentselected from a specified group, the substituent may be either the sameor different at each position.

As described herein, when the term “optionally substituted” precedes alist, said term refers to all of the subsequent substitutable groups inthat list. For example, if X is halogen; optionally substituted C₁₋₃alkyl or phenyl; X may be either optionally substituted alkyl oroptionally substituted phenyl. Likewise, if the term “optionallysubstituted” follows a list, said term also refers to all of thesubstitutable groups in the prior list unless otherwise indicated. Forexample: if X is halogen, C₁₋₃ alkyl, or phenyl, wherein X is optionallysubstituted by J^(X), then both C₁₋₃ alkyl and phenyl may be optionallysubstituted by J^(X). As is apparent to one having ordinary skill in theart, groups such as H, halogen, NO₂, CN, NH₂, OH, or OCF₃ would not beincluded because they are not substitutable groups. As is also apparentto a skilled person, a heteroaryl or heterocyclic ring containing an NHgroup can be optionally substituted by replacing the hydrogen atom withthe substituent. If a substituent radical or structure is not identifiedor defined as “optionally substituted,” the substituent radical orstructure is unsubstituted.

Combinations of substituents envisioned by this invention are preferablythose that result in the formation of stable or chemically feasiblecompounds. The term “stable,” as used herein, refers to compounds thatare not substantially altered when subjected to conditions to allow fortheir production, detection, and, preferably, their recovery,purification, and use for one or more of the purposes disclosed herein.In some embodiments, a stable compound or chemically feasible compoundis one that is not substantially altered when kept at a temperature of40° C. or less, in the absence of moisture or other chemically reactiveconditions, for at least a week.

The term “alkyl” or “alkyl group,” as used herein, means astraight-chain (i.e., unbranched) or branched, substituted orunsubstituted hydrocarbon chain that is completely saturated. Unlessotherwise specified, alkyl groups contain 1-8 carbon atoms. In someembodiments, alkyl groups contain 1-6 carbon atoms, and in yet otherembodiments, alkyl groups contain 1-4 carbon atoms (represented as “C₁₋₄alkyl”). In other embodiments, alkyl groups are characterized as “C₀₋₄alkyl” representing either a covalent bond or a C₁₋₄ alkyl chain.Examples of alkyl groups include methyl, ethyl, propyl, butyl,isopropyl, isobutyl, sec-butyl, and tent-butyl. The term “alkylene,” asused herein, represents a saturated divalent straight or branched chainhydrocarbon group and is exemplified by methylene, ethylene,isopropylene and the like. The term “alkylidene,” as used herein,represents a divalent straight chain alkyl linking group. The term“alkenyl,” as used herein, represents monovalent straight or branchedchain hydrocarbon group containing one or more carbon-carbon doublebonds. The term “alkynyl,” as used herein, represents a monovalentstraight or branched chain hydrocarbon group containing one or morecarbon-carbon triple bonds.

The term “cycloalkyl” (or “carbocycle”) refers to a monocyclic C₃-C₈hydrocarbon or bicyclic C₈-C₁₂ hydrocarbon that is completely saturatedand has a single point of attachment to the rest of the molecule, andwherein any individual ring in said bicyclic ring system has 3-7members. Suitable cycloalkyl groups include, but are not limited to,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

The term “heterocycle,” “heterocyclyl,” “heterocycloalkyl,” or“heterocyclic” as used herein refers to a monocyclic, bicyclic, ortricyclic ring system in which at least one ring in the system containsone or more heteroatoms, which is the same or different, and that iscompletely saturated or that contains one or more units of unsaturation,but which is not aromatic, and that has a single point of attachment tothe rest of the molecule. In some embodiments, the “heterocycle,”“heterocyclyl,” “heterocycloalkyl,” or “heterocyclic” group has three tofourteen ring members in which one or more ring members is a heteroatomindependently selected from oxygen, sulfur, nitrogen, or phosphorus, andeach ring in the system contains 3 to 8 ring members.

Examples of heterocyclic rings include, but are not limited to, thefollowing monocycles: 2-tetrahydrofuranyl, 3-tetrahydrofuranyl,2-tetrahydrothiophenyl, 3-tetrahydrothiophenyl, 2-morpholino,3-morpholino, 4-morpholino, 2-thiomorpholino, 3-thiomorpholino,4-thiomorpholino, 1-pyrrolidinyl, 2-pyrrolidinyl, 3-pyrrolidinyl,1-tetrahydropiperazinyl, 2-tetrahydropiperazinyl,3-tetrahydropiperazinyl, 1-piperidinyl, 2-piperidinyl, 3-piperidinyl,1-pyrazolinyl, 3-pyrazolinyl, 4-pyrazolinyl, 5-pyrazolinyl,1-piperidinyl, 2-piperidinyl, 3-piperidinyl, 4-piperidinyl,2-thiazolidinyl, 3-thiazolidinyl, 4-thiazolidinyl, 1-imidazolidinyl,2-imidazolidinyl, 4-imidazolidinyl, 5-imidazolidinyl; and the followingbicycles: 3-1H-benzimidazol-2-one, 3-(1-alkyl)-benzimidazol-2-one,indolinyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, benzothiolane,benzodithiane, and 1,3-dihydro-imidazol-2-one.

The term “heteroatom” means one or more of oxygen, sulfur, nitrogen, orphosphorus, including any oxidized form of nitrogen, sulfur, orphosphorus; the quaternized form of any basic nitrogen; or asubstitutable nitrogen of a heterocyclic ring, for example N (as in3,4-dihydro-2H-pyrrolyl), NH (as in pyrrolidinyl) or NR⁺ (as inN-substituted pyrrolidinyl).

The term “unsaturated,” as used herein, means that a moiety has one ormore units of unsaturation.

The term “alkoxy,” or “thioalkyl,” as used herein, refers to an alkylgroup, as previously defined, attached to the principal carbon chainthrough an oxygen (“alkoxy”) or sulfur (“thioalkyl”) atom.

The terms “haloalkyl,” “haloalkenyl,” and “haloalkoxy” mean alkyl,alkenyl, or alkoxy, as the case may be, substituted with one or morehalogen atoms. The term “halogen” means F, Cl, Br, or I.

The term “aryl” used alone or as part of a larger moiety as in“aralkyl,” “aralkoxy,” or “aryloxyalkyl,” refers to a monocyclic,bicyclic, or tricyclic carbocyclic ring system having a total of six tofourteen ring members, wherein said ring system has a single point ofattachment to the rest of the molecule, at least one ring in the systemis aromatic and wherein each ring in the system contains 4 to 7 ringmembers. The term “aryl” may be used interchangeably with the term “arylring.” Examples of aryl rings include phenyl, naphthyl, and anthracene.

The term “heteroaryl,” used alone or as part of a larger moiety as in“heteroaralkyl,” or “heteroarylalkoxy,” refers to a monocyclic,bicyclic, and tricyclic ring system having a total of five to fourteenring members, wherein said ring system has a single point of attachmentto the rest of the molecule, at least one ring in the system isaromatic, at least one ring in the system contains one or moreheteroatoms independently selected from nitrogen, oxygen, sulfur orphosphorus, and wherein each ring in the system contains 4 to 7 ringmembers. The term “heteroaryl” may be used interchangeably with the term“heteroaryl ring” or the term “heteroaromatic.”

Further examples of heteroaryl rings include the following monocycles:2-furanyl, 3-furanyl, N-imidazolyl, 2-imidazolyl, 4-imidazolyl,5-imidazolyl, 3-isoxazolyl, 4-isoxazolyl, 5-isoxazolyl, 2-oxazolyl,4-oxazolyl, 5-oxazolyl, N-pyrrolyl, 2-pyrrolyl, 3-pyrrolyl, 2-pyridyl,3-pyridyl, 4-pyridyl, 2-pyrimidinyl, 4-pyrimidinyl, 5-pyrimidinyl,pyridazinyl (e.g., 3-pyridazinyl), 2-thiazolyl, 4-thiazolyl,5-thiazolyl, tetrazolyl (e.g., 5-tetrazolyl), triazolyl (e.g.,2-triazolyl and 5-triazolyl), 2-thienyl, 3-thienyl, pyrazolyl (e.g.,2-pyrazolyl), isothiazolyl, 1,2,3-oxadiazolyl, 1,2,5-oxadiazolyl,1,2,4-oxadiazolyl, 1,2,3-triazolyl, 1,2,3-thiadiazolyl,1,3,4-thiadiazolyl, 1,2,5-thiadiazolyl, pyrazinyl, 1,3,5-triazinyl, andthe following bicycles: benzimidazolyl, benzofuryl, benzothiophenyl,indolyl (e.g., 2-indolyl), purinyl, quinolinyl (e.g., 2-quinolinyl,3-quinolinyl, 4-quinolinyl), and isoquinolinyl (e.g., 1-isoquinolinyl,3-isoquinolinyl, or 4-isoquinolinyl).

As described herein, a bond drawn from a substituent to the center ofone ring within a multiple-ring system (as shown below) representssubstitution of the substituent at any substitutable position in any ofthe rings within the multiple ring system. For example, Structure arepresents possible substitution in any of the positions shown inStructure b.

This also applies to multiple ring systems fused to optional ringsystems (which would be represented by dotted lines). For example, inStructure c, X is an optional substituent both for ring A and ring B.

If, however, two rings in a multiple ring system each have differentsubstituents drawn from the center of each ring, then, unless otherwisespecified, each substituent only represents substitution on the ring towhich it is attached. For example, in Structure d, Y is an optionallysubstituent for ring A only, and X is an optional substituent for ring Bonly.

The term “protecting group,” as used herein, represent those groupsintended to protect a functional group, such as, for example, analcohol, amine, carboxyl, carbonyl, etc., against undesirable reactionsduring synthetic procedures. Commonly used protecting groups aredisclosed in Greene and Wuts, Protective Groups In Organic Synthesis,3^(rd) Edition (John Wiley & Sons, New York, 1999), which isincorporated herein by reference. Examples of nitrogen protecting groupsinclude acyl, aroyl, or carbamyl groups such as formyl, acetyl,propionyl, pivaloyl, t-butylacetyl, 2-chloroacetyl, 2-bromoacetyl,trifluoroacetyl, trichloroacetyl, phthalyl, o-nitrophenoxyacetyl,α-chlorobutyryl, benzoyl, 4-chlorobenzoyl, 4-bromobenzoyl,4-nitrobenzoyl and chiral auxiliaries such as protected or unprotectedD, L or D, L-amino acids such as alanine, leucine, phenylalanine and thelike; sulfonyl groups such as benzenesulfonyl, p-toluenesulfonyl and thelike; carbamate groups such as benzyloxycarbonyl,p-chlorobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl,p-nitrobenzyloxycarbonyl, 2-nitrobenzyloxycarbonyl,p-bromobenzyloxycarbonyl, 3,4-dimethoxybenzyloxycarbonyl,3,5-dimethoxybenzyloxycarbonyl, 2,4-dimethoxybenzyloxycarbonyl,4-methoxybenzyloxycarbonyl, 2-nitro-4,5-dimethoxybenzyloxycarbonyl,3,4,5-trimethoxybenzyloxycarbonyl,1-(p-biphenylyl)-1-methylethoxycarbonyl,α,α-dimethyl-3,5-dimethoxybenzyloxycarbonyl, benzhydryloxycarbonyl,t-butyloxycarbonyl, diisopropylmethoxycarbonyl, isopropyloxycarbonyl,ethoxycarbonyl, methoxycarbonyl, allyloxycarbonyl,2,2,2,-trichloroethoxycarbonyl, phenoxycarbonyl, 4-nitrophenoxycarbonyl, fluorenyl-9-methoxycarbonyl, cyclopentyloxycarbonyl,adamantyloxycarbonyl, cyclohexyloxycarbonyl, phenylthiocarbonyl and thelike, arylalkyl groups such as benzyl, triphenylmethyl, benzyloxymethyland the like and silyl groups such as trimethylsilyl and the like.Preferred N-protecting groups are formyl, acetyl, benzoyl, pivaloyl,t-butylacetyl, alanyl, phenylsulfonyl, benzyl, t-butyloxycarbonyl (Boc)and benzyloxycarbonyl (Cbz). Examples of hydroxyl protecting groupsinclude ethers, such as tetrahydropyranyl, tert butyl, benzyl, allyl,and the like; silyl ethers such as trimethyl silyl, triethyl silyl,triisopropylsilyl, tert-butyl diphenyl silyl, and the like; esters suchas acetyl, trifluoroacetyl, and the like; and carbonates. Hydroxylprotecting groups also include those appropriate for the protection ofphenols.

Unless otherwise depicted or stated, structures recited herein are meantto include all isomeric (e.g., enantiomeric, diastereomeric, andgeometric (or conformational)) forms of the structure; for example, theR and S configurations for each asymmetric center, (Z) and (E) doublebond isomers, and (Z) and (E) conformational isomers. Therefore, singlestereochemical isomers as well as enantiomeric, diastereomeric, andgeometric (or conformational) mixtures of the present compounds arewithin the scope of the invention. Compounds that have been drawn withstereochemical centers defined, usually through the use of a hatched (

) or bolded (

) bond, are stereochemically pure, but with the absolute stereochemistrystill undefined. Such compounds can have either the R or Sconfiguration. In those cases where the absolute configuration has beendetermined, the chiral center(s) are labeled (R) or (S) in the drawing.

Unless otherwise stated, all tautomeric forms of the compounds of theinvention are within the scope of the invention. Additionally, unlessotherwise stated, structures depicted herein are also meant to includecompounds that differ only in the presence of one or more isotopicallyenriched atoms. For example, compounds having the present structuresexcept for the replacement of hydrogen by deuterium or tritium, or thereplacement of a carbon by a ¹³C- or ¹⁴C-enriched carbon are within thescope of this invention. Such compounds are useful, for example, asanalytical tools, probes in biological assays, or as DNA-PK inhibitorswith an improved therapeutic profile.

Description of Compounds of the Invention

In one aspect, the invention features compounds having the formula:

wherein

-   Ring A is a ring system selected from

-   Ring B is a ring system selected from

-    wherein Ring B is optionally substituted with up to 4 fluorine    atoms, up to two OH or up to two C₁₋₄alkyl which is optionally    substituted with up to 3 fluorine atoms, up to two OH, or up to two    OC₁₋₂alkyl groups;-   Ring C is a cyclohexane or a cyclobutane ring;-   X is —NH—, —O—, or —OC₁₋₄ alkyl-;-   each of R¹ and R² is, independently, hydrogen, —C(O)NHR⁴, —C(O)OR⁴,    —NHC(O)R⁴, —NHC(O)OR⁴, —NHC(O)NHR⁴, —NHS(O)₂R⁴, —C₀₋₄ alkyl-NHR⁴, or    —OR⁴, wherein R¹ and R² cannot simultaneously be hydrogen, and    wherein R¹ and R² and the intervening carbon atom can form a dioxane    or dioxolane ring;-   R³ is hydrogen, —C₁₋₄alkyl, fluoro, chloro, —OC₁₋₂alkyl, —C(O)H,    —C(O)OH, —C(O)OC₁₋₂alkyl, —CN, —C(O)NHC₁₋₂alkyl, or —C(O)NH₂,    wherein each of said R³ alkyl is optionally substituted with up to 3    fluorine atoms, up to two OH, or up to two OC₁₋₂alkyl groups;-   R⁴ is hydrogen, C₁₋₄alkyl, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₅cycloalkyl,    phenyl, a 5-10-membered monocyclic or bicyclic heteroaryl ring    selected from pyrrole, imidazole, pyrazole, triazole, thiazole,    isothiazole, oxazole, pyridine, pyrimidine, pyrimidinone, pyrazine,    pyridazine, or quinoline, or a 4-10-membered monocyclic or bicyclic    heterocyclyl ring selected from oxetane, tetrahydrofuran,    tetrahydropyran, dihydroisoxazole, pyrimidine-2,4(1H,3H)-dione,    dihydrofuropyrimidine, dihydropyranopyrimidine,    dihydropyrrolopyrimidine, tetrahydropteridine, or    tetrahydropyridopyrimidine, wherein each of said R⁴ groups is    optionally substituted with up to four Br, Cl, F, or C₁₋₄alkyl, up    to three CN, NO₂, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₆cycloalkyl, C₀₋₄    alkyl-C₃₋₅ cycloalkyl, C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄    alkyl-C₃₋₅ cycloalkyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅    cycloalkyl, C₀₋₄ alkyl—C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄    alkyl)₂, C(O)NH(C₀₋₄ alkyl-C₃₋₅ cycloalkyl), CH₂OR⁵, C₀₋₄    alkyl—C(O)R⁵, C₀₋₄ alkyl—C(O)N(R⁵)₂, C₀₋₄ alkyl—C(O)OR⁵, C₀₋₄    alkyl—NHC(O)R⁵, C₀₋₄ alkyl-N(R⁵)₂, a heterocyclic ring system    selected from oxetane, azetidine, tetrahydrofuran, dihydropyran,    tetrahydropyran, morpholine, piperidine, pyrrolidine or piperazine,    a heteroaryl ring system selected from furan, oxazole, oxadiazole,    pyrrole, pyrazole, triazole, oxadiazole or tetrazole, or up to two    OR⁵, wherein each of said optional R⁴ substituents is optionally    substituted with up to four fluorine atoms, up to two C₁₋₄alkyl    groups, up to two OH groups, up to two OC₁₋₄alkyl groups, up to two    SC₁₋₄alkyl groups, a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄ alkyl, or a    C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl; and    each R⁵ is, independently, hydrogen, C₁₋₄alkyl, a 5-6-membered    heteroaryl selected from imidazole, triazole, thiazole, pyridine, or    pyrimidine, a 4-6-membered heterocyclyl selected from oxetane,    tetrahydrofuran, or tetrahydropyran, and each R⁵ group is optionally    substituted with chloro, up to three fluorine atoms, up to two    C₁₋₂alkyl, CH₂OH, CN, up to two OH, up to two OC₁₋₂alkyl, a    spirooxetane, pyrrolidine, or triazole, or two R⁵ groups together    with the intervening nitrogen atom form a morpholine ring, azetidine    ring, pyrrolidine ring, piperidine ring, or piperazine ring.

In one embodiment, Ring C is cyclobutane.

In another aspect, the invention features compounds having the formula:

wherein R¹ and R² are as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R² is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R² is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In one embodiment, R¹ is —C₀₋₄ alkyl-NHR⁴.

In another embodiment, X is —O— or —OC₁₋₄ alkyl-.

In one embodiment, Ring C is cyclohexane.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In one embodiment, X is —NH—.

In another aspect, the invention features compounds having the formula:

wherein R² is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R² is as defined for compounds of formula I.

In one embodiment, R² is —C₀₋₄ alkyl-NHR⁴ or —OR⁴.

In another embodiment, R² is —NHR⁴ or —OR⁴.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In one embodiment, R¹ is —C₀₋₄ alkyl-NHR⁴ or —OR⁴.

In another embodiment, R¹ is —NHR⁴ or —OR⁴.

In another embodiment, X is —O—.

In another aspect, the invention features compounds having the formula:

wherein R² is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R² is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In another aspect, the invention features compounds having the formula:

wherein R¹ is as defined for compounds of formula I.

In one embodiment, R¹ is —C₀₋₄ alkyl-NHR⁴ or —OR⁴.

In another embodiment, R¹ is —NHR⁴ or —OR⁴.

In another aspect, the invention features compounds having the formula:

wherein Y is —O— or —NH—.

In one embodiment of compounds having formula I, II, II-A, II-A-1, II-B,II-B-1, III, III-A, III-A-1, III-A-2, III-B, III-B-1, III-B-2, III-C,III-C-1, III-C-2, III-D, III-D-1, III-D-2, or III-D-3,

In another embodiment,

In another embodiment, R³ is hydrogen.

In another embodiment, R⁴ is hydrogen, C₁₋₄alkyl, C₂₋₄alkenyl,C₂₋₄alkynyl, C₃₋₅cycloalkyl, phenyl, wherein each of said R⁴ groups isoptionally substituted with up to four Br, Cl, F, or C₁₋₄alkyl, up tothree CN, NO₂, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₆cycloalkyl, C₀₋₄ alkyl-C₃₋₅cycloalkyl, C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅cycloalkyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₀₋₄alkyl—C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄ alkyl)₂, C(O)NH(C₀₋₄alkyl-C₃₋₅ cycloalkyl), CH₂OR⁵, C₀₋₄ alkyl—C(O)R⁵, C₀₋₄alkyl-C(O)N(R⁵)₂, C₀₋₄ alkyl—C(O)OR⁵, C₀₋₄ alkyl-NHC(O)R⁵, C₀₋₄alkyl-N(R⁵)₂, a heterocyclic ring system selected from oxetane,azetidine, tetrahydrofuran, dihydropyran, tetrahydropyran, morpholine,piperidine, pyrrolidine or piperazine, a heteroaryl ring system selectedfrom furan, oxazole, oxadiazole, pyrrole, pyrazole, triazole, oxadiazoleor tetrazole, or up to two OR⁵, wherein each of said optional R⁴substituents is optionally substituted with up to four fluorine atoms,up to two C₁₋₄alkyl groups, up to two OH groups, up to two OC₁₋₄alkylgroups, up to two SC₁₋₄alkyl groups, a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄alkyl, or a C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl; and

each R⁵ is, independently, hydrogen, C₁₋₄alkyl, a 5-6-memberedheteroaryl selected from imidazole, triazole, thiazole, pyridine, orpyrimidine, a 4-6-membered heterocyclyl selected from oxetane,tetrahydrofuran, or tetrahydropyran, and each R⁵ group is optionallysubstituted with chloro, up to three fluorine atoms, up to twoC₁₋₂alkyl, CH₂OH, CN, up to two OH, up to two OC₁₋₂alkyl, aspirooxetane, pyrrolidine, or triazole, or two R⁵ groups together withthe intervening nitrogen atom form a morpholine ring, azetidine ring,pyrrolidine ring, piperidine ring, or piperazine ring.

In another embodiment, R⁴ is a 5-10-membered monocyclic or bicyclicheteroaryl ring selected from pyrrole, imidazole, pyrazole, triazole,thiazole, isothiazole, oxazole, pyridine, pyrimidine, pyrimidinone,pyrazine, pyridazine, or quinoline, wherein each of said R⁴ groups isoptionally substituted with up to four Br, Cl, F, or C₁₋₄alkyl, up tothree CN, NO₂, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₆cycloalkyl, C₀₋₄ alkyl-C₃₋₅cycloalkyl, C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅cycloalkyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₀₋₄alkyl—C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄ alkyl)₂, C(O)NH(C₀₋₄alkyl-C₃₋₅ cycloalkyl), CH₂OR⁵, C₀₋₄ alkyl—C(O)R⁵, C₀₋₄alkyl—C(O)N(R⁵)₂, C₀₋₄ alkyl—C(O)OR⁵, C₀₋₄ alkyl-NHC(O)R⁵, C₀₋₄alkyl-N(R⁵)₂, a heterocyclic ring system selected from oxetane,azetidine, tetrahydrofuran, dihydropyran, tetrahydropyran, morpholine,piperidine, pyrrolidine or piperazine, a heteroaryl ring system selectedfrom furan, oxazole, oxadiazole, pyrrole, pyrazole, triazole, oxadiazoleor tetrazole, or up to two OR⁵, wherein each of said optional R⁴substituents is optionally substituted with up to four fluorine atoms,up to two C₁₋₄alkyl groups, up to two OH groups, up to two OC₁₋₄alkylgroups, up to two SC₁₋₄alkyl groups, a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄alkyl, or a C(O)CO₀₋₄ alkyl-C₃₋₅ cycloalkyl; and

each R⁵ is, independently, hydrogen, C₁₋₄alkyl, a 5-6-memberedheteroaryl selected from imidazole, triazole, thiazole, pyridine, orpyrimidine, a 4-6-membered heterocyclyl selected from oxetane,tetrahydrofuran, or tetrahydropyran, and each R⁵ group is optionallysubstituted with chloro, up to three fluorine atoms, up to twoC₁₋₂alkyl, CH₂OH, CN, up to two OH, up to two OC₁₋₂alkyl, aspirooxetane, pyrrolidine, or triazole, or two R⁵ groups together withthe intervening nitrogen atom form a morpholine ring, azetidine ring,pyrrolidine ring, piperidine ring, or piperazine ring.

In yet another embodiment, R⁴ is pyridine or pyrimidine, which isoptionally substituted with up to four Br, Cl, F, or C₁₋₄alkyl, up tothree CN, NO₂, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₆cycloalkyl, C₀₋₄ alkyl-C₃₋₅cycloalkyl, C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅cycloalkyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₀₋₄alkyl—C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄ alkyl)₂, C(O)NH(C₀₋₄alkyl-C₃₋₅ cycloalkyl), CH₂OR⁵, C₀₋₄ alkyl—C(O)R⁵, C₀₋₄alkyl—C(O)N(R⁵)₂, C₀₋₄ alkyl—C(O)OR⁵, C₀₋₄ alkyl-NHC(O)R⁵, C₀₋₄alkyl-N(R⁵)₂, a heterocyclic ring system selected from oxetane,azetidine, tetrahydrofuran, dihydropyran, tetrahydropyran, morpholine,piperidine, pyrrolidine or piperazine, a heteroaryl ring system selectedfrom furan, oxazole, oxadiazole, pyrrole, pyrazole, triazole, oxadiazoleor tetrazole, or up to two OR⁵, wherein each of said optional R⁴substituents is optionally substituted with up to four fluorine atoms,up to two C₁₋₄alkyl groups, up to two OH groups, up to two OC₁₋₄alkylgroups, up to two SC₁₋₄alkyl groups, a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄alkyl, or a C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl; and

each R⁵ is, independently, hydrogen, C₁₋₄alkyl, a 5-6-memberedheteroaryl selected from imidazole, triazole, thiazole, pyridine, orpyrimidine, a 4-6-membered heterocyclyl selected from oxetane,tetrahydrofuran, or tetrahydropyran, and each R⁵ group is optionallysubstituted with chloro, up to three fluorine atoms, up to twoC₁₋₂alkyl, CH₂OH, CN, up to two OH, up to two OC₁₋₂alkyl, aspirooxetane, pyrrolidine, or triazole, or two R⁵ groups together withthe intervening nitrogen atom form a morpholine ring, azetidine ring,pyrrolidine ring, piperidine ring, or piperazine ring.

In another embodiment, R⁴ is a 4-10-membered monocyclic or bicyclicheterocyclyl ring selected from oxetane, tetrahydrofuran,tetrahydropyran, dihydroisoxazole, pyrimidine-2,4(1H,3H)-dione,dihydrofuropyrimidine, dihydropyranopyrimidine,dihydropyrrolopyrimidine, tetrahydropteridine, ortetrahydropyridopyrimidine, wherein each of said R⁴ groups is optionallysubstituted with up to four Br, Cl, F, or C₁₋₄alkyl, up to three CN,NO₂, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₆cycloalkyl, C₀₋₄ alkyl-C₃₋₅cycloalkyl, C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅cycloalkyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₀₋₄alkyl—C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄ alkyl)₂, C(O)NH(C₀₋₄alkyl-C₃₋₅ cycloalkyl), CH₂OR⁵, C₀₋₄ alkyl—C(O)R⁵, C₀₋₄alkyl—C(O)N(R⁵)₂, C₀₋₄ alkyl—C(O)OR⁵, C₀₋₄ alkyl-NHC(O)R⁵, C₀₋₄alkyl-N(R⁵)₂, a heterocyclic ring system selected from oxetane,azetidine, tetrahydrofuran, dihydropyran, tetrahydropyran, morpholine,piperidine, pyrrolidine or piperazine, a heteroaryl ring system selectedfrom furan, oxazole, oxadiazole, pyrrole, pyrazole, triazole, oxadiazoleor tetrazole, or up to two OR⁵, wherein each of said optional R⁴substituents is optionally substituted with up to four fluorine atoms,up to two C₁₋₄alkyl groups, up to two OH groups, up to two OC₁₋₄alkylgroups, up to two SC₁₋₄alkyl groups, a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄alkyl, or a C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl; and

each R⁵ is, independently, hydrogen, C₁₋₄alkyl, a 5-6-memberedheteroaryl selected from imidazole, triazole, thiazole, pyridine, orpyrimidine, a 4-6-membered heterocyclyl selected from oxetane,tetrahydrofuran, or tetrahydropyran, and each R⁵ group is optionallysubstituted with chloro, up to three fluorine atoms, up to twoC₁₋₂alkyl, CH₂OH, CN, up to two OH, up to two OC₁₋₂alkyl, aspirooxetane, pyrrolidine, or triazole, or two R⁵ groups together withthe intervening nitrogen atom form a morpholine ring, azetidine ring,pyrrolidine ring, piperidine ring, or piperazine ring.

In another aspect, the invention features compounds having the formula:

wherein

-   -   R³ is hydrogen, C₁₋₄alkyl, fluoro, chloro, —OC₁₋₂alkyl, or        —C(O)NH₂, —C(O)H, or —CN, wherein each of said R³ alkyl is        optionally substituted with OH or up to 3 fluorine atoms;    -   R⁴ is

-   -   X¹ is N, CH, CF, CCl, or CC₁₋₂ alkyl optionally substituted with        up to 3 fluorine atoms;    -   X² is N or CR^(4c); wherein X¹ and X² cannot simultaneously be        N,    -   each of R^(4a), R^(4b), and R^(4c) is, independently, hydrogen,        F, Cl, Br, CN, NO₂, C₁₋₄ alkyl, C₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₀₋₄        alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅ cycloalkyl,        C₂₋₄ alkenyl, C₂₋₄ alkynyl, C(O)OC₁₋₄ alkyl, C(O)CO₀₋₄        alkyl-C₃₋₅ cycloalkyl, C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄        alkyl)₂, C(O)NH(C₀₋₄ alkyl-C₃₋₅ cycloalkyl), a heterocyclic ring        system selected from oxetane, azetidine, tetrahydrofuran,        dihydropyran, tetrahydropyran, morpholine, piperidine, or        piperazine, or a heteroaryl ring system selected from furan,        oxazole, oxadiazole, pyrrole, pyrazole, triazole, or tetrazole,        or R^(4a), R^(4a), and the intervening atoms form a        dihydrofuran, a dihydropyran, or a tetrahydropiperidine        heterocyclic ring system;    -   wherein each of said R^(4a), R^(4b), or R^(4c) heterocyclic or        heteroaryl ring systems is optionally substituted with up to        four fluorine atoms, up to two C₁₋₄ alkyl, up to two OH groups,        a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄ alkyl, or a C(O)OC₀₋₄ alkyl-C₃₋₅        cycloalkyl; and    -   wherein each of said R^(4a), R^(4b), or R^(4c) alkyl or        cycloalkyl is optionally substituted with up to 2 non-geminal OH        groups or up to 3 fluorine atoms.

In one embodiment, R³ is hydrogen.

In another embodiment, each of X¹ and X² is, independently, CH or N.

In another embodiment, each of R^(4a) and R^(4b) is, independently, aheterocyclic ring system selected from oxetane, azetidine,tetrahydrofuran, dihydropyran, tetrahydropyran, morpholine, piperidine,or piperazine, wherein each of said R^(4a) or R^(4b) heterocyclic orheteroaryl ring systems is optionally substituted with up to fourfluorine atoms, up to two C₁₋₄ alkyl, up to two OH groups, a C(O)C₁₋₄alkyl, a C(O)OC₁₋₄ alkyl, or a C(O)CO₀₋₄ alkyl-C₃₋₅ cycloalkyl; andwherein each of said R^(4a) or R^(4b) alkyl or cycloalkyl is optionallysubstituted with up to 2 non-geminal OH groups or up to 3 fluorineatoms.

In another embodiment, each of R^(4a) and R^(4b) is, independently, aheteroaryl ring system selected from furan, oxazole, oxadiazole,pyrrole, pyrazole, triazole, or tetrazole, wherein each of said R^(4a)or R^(4b) heterocyclic or heteroaryl ring systems is optionallysubstituted with up to four fluorine atoms, up to two C₁₋₄ alkyl, up totwo OH groups, a C(O)C₁₋₄ alkyl, a C(O)OC₁₋₄ alkyl, or a C(O)OC₀₋₄alkyl-C₃₋₅ cycloalkyl; and wherein each of said R^(4a) or R^(4b) alkylor cycloalkyl is optionally substituted with up to 2 non-geminal OHgroups or up to 3 fluorine atoms.

In another embodiment, each of R^(4a) and R^(4b) is, independently,hydrogen, F, Cl, Br, CN, NO₂, C₁₋₄ alkyl, C₀₋₄ alkyl-C₃₋₅ cycloalkyl,C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₂₋₄alkenyl, C₂₋₄ alkynyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl,C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄ alkyl)₂, or C(O)NH(C₀₋₄ alkyl-C₃₋₅cycloalkyl), wherein each of said R^(4a) or R^(4b) heterocyclic orheteroaryl ring systems is optionally substituted with up to fourfluorine atoms, up to two C₁₋₄ alkyl, up to two OH groups, a C(O)C₁₋₄alkyl, a C(O)OC₁₋₄ alkyl, or a C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl; andwherein each of said R^(4a) or R^(4b) alkyl or cycloalkyl is optionallysubstituted with up to 2 non-geminal OH groups or up to 3 fluorineatoms.

In another embodiment, the invention features a compound selected fromthe group of compounds listed in Table 1.

In another embodiment, the invention features a compound selected fromthe group of compounds listed in Table 2.

Compositions, Formulations, and Administration of Compounds of theInvention

In another embodiment, the invention provides a pharmaceuticalcomposition comprising a compound of any of the formulae describedherein and a pharmaceutically acceptable excipient. In a furtherembodiment, the invention provides a pharmaceutical compositioncomprising a compound of Table 1. In a further embodiment, thecomposition additionally comprises an additional therapeutic agent.

According to another embodiment, the invention provides a compositioncomprising a compound of this invention or a pharmaceutically acceptablederivative thereof and a pharmaceutically acceptable carrier, adjuvant,or vehicle. In one embodiment, the amount of compound in a compositionof this invention is such that is effective to measurably inhibit aDNA-PK in a biological sample or in a patient. In another embodiment,the amount of compound in the compositions of this invention is suchthat is effective to measurably inhibit DNA-PK. In one embodiment, thecomposition of this invention is formulated for administration to apatient in need of such composition. In a further embodiment, thecomposition of this invention is formulated for oral administration to apatient.

The term “patient,” as used herein, means an animal, preferably amammal, and most preferably a human.

It will also be appreciated that certain of the compounds of presentinvention can exist in free form for treatment, or where appropriate, asa pharmaceutically acceptable derivative thereof. According to thepresent invention, a pharmaceutically acceptable derivative includes,but is not limited to, pharmaceutically acceptable prodrugs, salts,esters, salts of such esters, or any other adduct or derivative whichupon administration to a patient in need is capable of providing,directly or indirectly, a compound as otherwise described herein, or ametabolite or residue thereof As used herein, the term “inhibitoryactive metabolite or residue thereof” means that a metabolite or residuethereof is also an inhibitor of DNA-PK.

As used herein, the term “pharmaceutically acceptable salt” refers tothose salts which are, within the scope of sound medical judgment,suitable for use in contact with the tissues of humans and lower animalswithout undue toxicity, irritation, allergic response and the like.

Pharmaceutically acceptable salts are well known in the art. Forexample, S. M. Berge et al., describe pharmaceutically acceptable saltsin detail in J. Pharmaceutical Sciences, 66:1-19, 1977, which isincorporated herein by reference. Pharmaceutically acceptable salts ofthe compounds of this invention include those derived from suitableinorganic and organic acids and bases. Examples of pharmaceuticallyacceptable, nontoxic acid addition salts are salts of an amino groupformed with inorganic acids such as hydrochloric acid, hydrobromic acid,phosphoric acid, sulfuric acid and perchloric acid or with organic acidssuch as acetic acid, oxalic acid, maleic acid, tartaric acid, citricacid, succinic acid or malonic acid or by using other methods used inthe art such as ion exchange. Other pharmaceutically acceptable saltsinclude adipate, alginate, ascorbate, aspartate, benzenesulfonate,benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate,citrate, cyclopentanepropionate, digluconate, dodecylsulfate,ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate,gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide,2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, laurylsulfate, malate, maleate, malonate, methanesulfonate,2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate,pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate,pivalate, propionate, stearate, succinate, sulfate, tartrate,thiocyanate, p-toluenesulfonate, undecanoate, valerate salts, and thelike. Salts derived from appropriate bases include alkali metal,alkaline earth metal, ammonium and N⁺(C₁₋₄ alkyl)₄ salts. This inventionalso envisions the quaternization of any basic nitrogen-containinggroups of the compounds disclosed herein. Water or oil-soluble ordispersable products may be obtained by such quaternization.Representative alkali or alkaline earth metal salts include sodium,lithium, potassium, calcium, magnesium, and the like. Furtherpharmaceutically acceptable salts include, when appropriate, nontoxicammonium, quaternary ammonium, and amine cations formed usingcounterions such as halide, hydroxide, carboxylate, sulfate, phosphate,nitrate, C₁₋₈ sulfonate and aryl sulfonate.

As described above, the pharmaceutically acceptable compositions of thepresent invention additionally comprise a pharmaceutically acceptablecarrier, adjuvant, or vehicle, which, as used herein, includes any andall solvents, diluents, or other liquid vehicle, dispersion orsuspension aids, surface active agents, isotonic agents, thickening oremulsifying agents, preservatives, solid binders, lubricants and thelike, as suited to the particular dosage form desired. In Remington: TheScience and Practice of Pharmacy, 21st edition, 2005, ed. D. B. Troy,Lippincott Williams & Wilkins, Philadelphia, and Encyclopedia ofPharmaceutical Technology, eds. J. Swarbrick and J. C. Boylan,1988-1999, Marcel Dekker, New York, the contents of each of which isincorporated by reference herein, are disclosed various carriers used informulating pharmaceutically acceptable compositions and knowntechniques for the preparation thereof. Except insofar as anyconventional carrier medium is incompatible with the compounds of theinvention, such as by producing any undesirable biological effect orotherwise interacting in a deleterious manner with any othercomponent(s) of the pharmaceutically acceptable composition, its use iscontemplated to be within the scope of this invention.

Some examples of materials which can serve as pharmaceuticallyacceptable carriers include, but are not limited to, ion exchangers,alumina, aluminum stearate, lecithin, serum proteins, such as humanserum albumin, buffer substances such as phosphates, glycine, sorbicacid, or potassium sorbate, partial glyceride mixtures of saturatedvegetable fatty acids, water, salts or electrolytes, such as protaminesulfate, disodium hydrogen phosphate, potassium hydrogen phosphate,sodium chloride, zinc salts, colloidal silica, magnesium trisilicate,polyvinyl pyrrolidone, polyacrylates, waxes,polyethylene-polyoxypropylene-block polymers, wool fat, sugars such aslactose, glucose and sucrose; starches such as corn starch and potatostarch; cellulose and its derivatives such as sodium carboxymethylcellulose, ethyl cellulose and cellulose acetate; powdered tragacanth;malt; gelatin; talc; excipients such as cocoa butter and suppositorywaxes; oils such as peanut oil, cottonseed oil; safflower oil; sesameoil; olive oil; corn oil and soybean oil; glycols; such a propyleneglycol or polyethylene glycol; esters such as ethyl oleate and ethyllaurate; agar; buffering agents such as magnesium hydroxide and aluminumhydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer'ssolution; ethyl alcohol, and phosphate buffer solutions, as well asother non-toxic compatible lubricants such as sodium lauryl sulfate andmagnesium stearate, as well as coloring agents, releasing agents,coating agents, sweetening, flavoring and perfuming agents,preservatives and antioxidants can also be present in the composition,according to the judgment of the formulator.

The compositions of the present invention may be administered orally,parenterally, by inhalation spray, topically, rectally, nasally,buccally, vaginally or via an implanted reservoir. The term “parenteral”as used herein includes subcutaneous, intravenous, intramuscular,intra-articular, intra-synovial, intrasternal, intrathecal, intraocular,intrahepatic, intralesional, epidural, intraspinal, and intracranialinjection or infusion techniques. Preferably, the compositions areadministered orally, intraperitoneally or intravenously. Sterileinjectable forms of the compositions of this invention may be aqueous oroleaginous suspension. These suspensions may be formulated according totechniques known in the art using suitable dispersing or wetting agentsand suspending agents. The sterile injectable preparation may also be asterile injectable solution or suspension in a non-toxic parenterallyacceptable diluent or solvent, for example as a solution in1,3-butanediol. Among the acceptable vehicles and solvents that may beemployed are water, Ringer's solution and isotonic sodium chloridesolution. In addition, sterile, fixed oils are conventionally employedas a solvent or suspending medium.

For this purpose, any bland fixed oil may be employed includingsynthetic mono-or diglycerides. Fatty acids, such as oleic acid and itsglyceride derivatives are useful in the preparation of injectables, asare natural pharmaceutically-acceptable oils, such as olive oil orcastor oil, especially in their polyoxyethylated versions. These oilsolutions or suspensions may also contain a long-chain alcohol diluentor dispersant, such as carboxymethyl cellulose or similar dispersingagents that are commonly used in the formulation of pharmaceuticallyacceptable dosage forms including emulsions and suspensions. Othercommonly used surfactants, such as Tweens, Spans and other emulsifyingagents or bioavailability enhancers which are commonly used in themanufacture of pharmaceutically acceptable solid, liquid, or otherdosage forms may also be used for the purposes of formulation.

The pharmaceutically acceptable compositions of this invention may beorally administered in any orally acceptable dosage form including, butnot limited to, capsules, tablets, aqueous suspensions or solutions. Inthe case of tablets for oral use, carriers commonly used include lactoseand corn starch. Lubricating agents, such as magnesium stearate, arealso typically added. For oral administration in a capsule form, usefuldiluents include lactose and dried cornstarch. When aqueous suspensionsare required for oral use, the active ingredient is combined withemulsifying and suspending agents. If desired, certain sweetening,flavoring or coloring agents may also be added.

Alternatively, the pharmaceutically acceptable compositions of thisinvention may be administered in the form of suppositories for rectaladministration. These can be prepared by mixing the agent with asuitable non-irritating excipient that is solid at room temperature butliquid at rectal temperature and therefore will melt in the rectum torelease the drug. Such materials include cocoa butter, beeswax andpolyethylene glycols.

The pharmaceutically acceptable compositions of this invention may alsobe administered topically, especially when the target of treatmentincludes areas or organs readily accessible by topical application,including diseases of the eye, the skin, or the lower intestinal tract.Suitable topical formulations are readily prepared for each of theseareas or organs.

Topical application for the lower intestinal tract can be effected in arectal suppository formulation (see above) or in a suitable enemaformulation. Topically-transdermal patches may also be used.

For topical applications, the pharmaceutically acceptable compositionsmay be formulated in a suitable ointment containing the active componentsuspended or dissolved in one or more carriers. Carriers for topicaladministration of the compounds of this invention include, but are notlimited to, mineral oil, liquid petrolatum, white petrolatum, propyleneglycol, polyoxyethylene, polyoxypropylene compound, emulsifying wax andwater. Alternatively, the pharmaceutically acceptable compositions canbe formulated in a suitable lotion or cream containing the activecomponents suspended or dissolved in one or more pharmaceuticallyacceptable carriers. Suitable carriers include, but are not limited to,mineral oil, sorbitan monostearate, polysorbate 60, cetyl esters wax,cetearyl alcohol, 2-octyldodecanol, benzyl alcohol and water.

For ophthalmic use, the pharmaceutically acceptable compositions may beformulated, e.g., as micronized suspensions in isotonic, pH adjustedsterile saline or other aqueous solution, or, preferably, as solutionsin isotonic, pH adjusted sterile saline or other aqueous solution,either with or without a preservative such as benzylalkonium chloride.Alternatively, for ophthalmic uses, the pharmaceutically acceptablecompositions may be formulated in an ointment such as petrolatum. Thepharmaceutically acceptable compositions of this invention may also beadministered by nasal aerosol or inhalation. Such compositions areprepared according to techniques well-known in the art of pharmaceuticalformulation and may be prepared as solutions in saline, employing benzylalcohol or other suitable preservatives, absorption promoters to enhancebioavailability, fluorocarbons, and/or other conventional solubilizingor dispersing agents.

Most preferably, the pharmaceutically acceptable compositions of thisinvention are formulated for oral administration.

Liquid dosage forms for oral administration include, but are not limitedto, pharmaceutically acceptable emulsions, microemulsions, solutions,suspensions, syrups and elixirs. In addition to the active compounds,the liquid dosage forms may contain inert diluents commonly used in theart such as, for example, water or other solvents, solubilizing agentsand emulsifiers such as ethyl alcohol, isopropyl alcohol, ethylcarbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propyleneglycol, 1,3-butylene glycol, dimethylformamide, oils (in particular,cottonseed, groundnut, corn, germ, olive, castor, and sesame oils),glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fattyacid esters of sorbitan, and mixtures thereof. Besides inert diluents,the oral compositions can also include adjuvants such as wetting agents,emulsifying and suspending agents, sweetening, flavoring, and perfumingagents.

Injectable preparations, for example, sterile injectable aqueous oroleaginous suspensions may be formulated according to the known artusing suitable dispersing or wetting agents and suspending agents. Thesterile injectable preparation may also be a sterile injectablesolution, suspension or emulsion in a nontoxic parenterally acceptablediluent or solvent, for example, as a solution in 1,3-butanediol. Amongthe acceptable vehicles and solvents that may be employed are water,Ringer's solution, U.S.P. and isotonic sodium chloride solution. Inaddition, sterile, fixed oils are conventionally employed as a solventor suspending medium. For this purpose any bland fixed oil can beemployed including synthetic mono- or diglycerides. In addition, fattyacids such as oleic acid are used in the preparation of injectables.

The injectable formulations can be sterilized, for example, byfiltration through a bacterial-retaining filter, or by incorporatingsterilizing agents in the form of sterile solid compositions which canbe dissolved or dispersed in sterile water or other sterile injectablemedium prior to use.

In order to prolong the effect of a compound of the present invention,it is often desirable to slow the absorption of the compound fromsubcutaneous or intramuscular injection. This may be accomplished by theuse of a liquid suspension of crystalline or amorphous material withpoor water solubility. The rate of absorption of the compound thendepends upon its rate of dissolution that, in turn, may depend uponcrystal size and crystalline form. Alternatively, dissolving orsuspending the compound in an oil vehicle accomplishes delayedabsorption of a parenterally administered compound form. Injectabledepot forms are made by forming microencapsule matrices of the compoundin biodegradable polymers such as polylactide-polyglycolide. Dependingupon the ratio of compound to polymer and the nature of the particularpolymer employed, the rate of compound release can be controlled.Examples of other biodegradable polymers include poly(orthoesters) andpoly(anhydrides). Depot injectable formulations are also prepared byentrapping the compound in liposomes or microemulsions that arecompatible with body tissues.

Compositions for rectal or vaginal administration are preferablysuppositories which can be prepared by mixing the compounds of thisinvention with suitable non-irritating excipients or carriers such ascocoa butter, polyethylene glycol or a suppository wax which are solidat ambient temperature but liquid at body temperature and therefore meltin the rectum or vaginal cavity and release the active compound.

Solid dosage forms for oral administration include capsules, tablets,pills, powders, and granules. In such solid dosage forms, the activecompound is mixed with at least one inert, pharmaceutically acceptableexcipient or carrier such as sodium citrate or dicalcium phosphateand/or a) fillers or extenders such as starches, lactose, sucrose,glucose, mannitol, and silicic acid, b) binders such as, for example,carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone,sucrose, and acacia, c) humectants such as glycerol, d) disintegratingagents such as agar-agar, calcium carbonate, potato or tapioca starch,alginic acid, certain silicates, and sodium carbonate, e) solutionretarding agents such as paraffin, f) absorption accelerators such asquaternary ammonium compounds, g) wetting agents such as, for example,cetyl alcohol and glycerol monostearate, h) absorbents such as kaolinand bentonite clay, and i) lubricants such as talc, calcium stearate,magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate,and mixtures thereof. In the case of capsules, tablets and pills, thedosage form may also comprise buffering agents.

Solid compositions of a similar type may also be employed as fillers insoft and hard-filled gelatin capsules using such excipients as lactoseor milk sugar as well as high molecular weight polyethylene glycols andthe like. The solid dosage forms of tablets, dragees, capsules, pills,and granules can be prepared with coatings and shells such as entericcoatings and other coatings well known in the pharmaceutical formulatingart. They may optionally contain opacifying agents and can also be of acomposition that they release the active ingredient(s) only, orpreferentially, in a certain part of the intestinal tract, optionally,in a delayed manner. Examples of embedding compositions that can be usedinclude polymeric substances and waxes. Solid compositions of a similartype may also be employed as fillers in soft and hard-filled gelatincapsules using such excipients as lactose or milk sugar as well as highmolecular weight polethylene glycols and the like.

The active compounds can also be in micro-encapsulated form with one ormore excipients as noted above. The solid dosage forms of tablets,dragees, capsules, pills, and granules can be prepared with coatings andshells such as enteric coatings, release controlling coatings and othercoatings well known in the pharmaceutical formulating art. In such soliddosage forms the active compound may be admixed with at least one inertdiluent such as sucrose, lactose or starch. Such dosage forms may alsocomprise, as is normal practice, additional substances other than inertdiluents, e.g., tableting lubricants and other tableting aids such amagnesium stearate and microcrystalline cellulose. In the case ofcapsules, tablets and pills, the dosage forms may also comprisebuffering agents. They may optionally contain opacifying agents and canalso be of a composition that they release the active ingredient(s)only, or preferentially, in a certain part of the intestinal tract,optionally, in a delayed manner. Examples of embedding compositions thatcan be used include polymeric substances and waxes.

Dosage forms for topical or transdermal administration of a compound ofthis invention include ointments, pastes, creams, lotions, gels,powders, solutions, sprays, inhalants or patches. The active componentis admixed under sterile conditions with a pharmaceutically acceptablecarrier and any needed preservatives or buffers as may be required.Ophthalmic formulation, eardrops, and eye drops are also contemplated asbeing within the scope of this invention. Additionally, the presentinvention contemplates the use of transdermal patches, which have theadded advantage of providing controlled delivery of a compound to thebody. Such dosage forms can be made by dissolving or dispensing thecompound in the proper medium. Absorption enhancers can also be used toincrease the flux of the compound across the skin. The rate can becontrolled by either providing a rate controlling membrane or bydispersing the compound in a polymer matrix or gel.

The compounds of the invention are preferably formulated in dosage unitform for ease of administration and uniformity of dosage. The expression“dosage unit form” as used herein refers to a physically discrete unitof agent appropriate for the patient to be treated. It will beunderstood, however, that the total daily usage of the compounds andcompositions of the present invention will be decided by the attendingphysician within the scope of sound medical judgment. The specificeffective dose level for any particular patient or organism will dependupon a variety of factors including the disorder being treated and theseverity of the disorder; the activity of the specific compoundemployed; the specific composition employed; the age, body weight,general health, sex and diet of the patient; the time of administration,route of administration, and rate of excretion of the specific compoundemployed; the duration of the treatment; drugs used in combination orcoincidental with the specific compound employed, and like factors wellknown in the medical arts.

The amount of the compounds of the present invention that may becombined with the carrier materials to produce a composition in a singledosage form will vary depending upon the host treated, the particularmode of administration. Preferably, the compositions should beformulated so that a dosage of between 0.01-100 mg/kg body weight/day ofthe inhibitor can be administered to a patient receiving thesecompositions.

Depending upon the particular proliferative condition or cancer to betreated, additional therapeutic agents, which are normally administeredto treat or prevent that condition, may also be present in thecompositions of this invention. As used herein, additional therapeuticagents which are normally administered to treat or prevent a particularproliferative condition or cancer are known as “appropriate for thedisease, or condition, being treated.” Examples of additionaltherapeutic agents are provided infra.

The amount of additional therapeutic agent present in the compositionsof this invention will be no more than the amount that would normally beadministered in a composition comprising that therapeutic agent as theonly active agent. Preferably the amount of additional therapeutic agentin the presently disclosed compositions will range from about 50% to100% of the amount normally present in a composition comprising thatagent as the only therapeutically active agent.

Uses of the Compounds and Compositions of the Invention

In one embodiment, the invention provides a method of sensitizing a cellto a theraputic agent or a disease state that induces a DNA lesioncomprising the step of contacting the cell with one or more DNA-PKinhibitors of formulae I, II, or III, or subformula thereof (e.g.,formulae I-A, I-A-1, I-A-2, I-B, I-B-1, I-B-2, I-C, I-C-1, I-C-2, I-C-3,I-C-4, I-D, I-D-1, I-D-2, I-D-3, I-D-4, or I-D-5).

The invention further provides methods of potentiating a therapeuticregimen for treatment of cancer comprising the step of administering toan individual in need thereof an effective amount of a DNA-PK inhibitorof formula I, II, or III, or a subformula thereof. In one aspect, thetherapeutic regimen for treatment of cancer includes radiation therapy.

Compounds of the invention are useful in instances where radiationtherapy is indicated to enhance the therapeutic benefit of suchtreatment. In addition, radiation therapy frequently is indicated as anadjuvent to surgery in the treatment of cancer. The goal of radiationtherapy in the adjuvant setting is to reduce the risk of recurrence andenhance disease-free survival when the primary tumor has beencontrolled. Adjuvant radiation therapy is indicated in several diseasesincluding colon, rectal, lung, gastroesophageal, and breast cancers asdescribed below.

The invention also can be practiced by including another anti-cancerchemotherapeutic agent with a compound of the invention in a therapeuticregimen for the treatment of cancer, with or without radiation therapy.The combination of a DNA-PK inhibitor compound of the invention withsuch other agents can potentiate the chemotherapeutic protocol. Forexample, the inhibitor compound of the invention can be administeredwith etoposide or bleomycin, agents known to cause DNA strand breakage.

The invention further relates to radiosensitizing tumor cells utilizinga compound of formula I, II, or III, or a subformula thereof. Thepreferred compounds are those as described for the pharmaceuticalcompositions of the invention. A compound that can “radiosensitize” acell, as used herein, is defined as a molecule, preferably a lowmolecular weight molecule, administered to animals in therapeuticallyeffective amount to increase the sensitivity of cells to electromagneticradiation and/or to promote the treatment of diseases that are treatablewith electromagnetic radiation (e.g., X-rays). Diseases that aretreatable with electromagnetic radiation include neoplastic diseases,benign and malignant tumors, and cancerous cells.

The present invention also provides methods of treating cancer in ananimal that includes administering to the animal an effective amount ofa DNA-PK inhibitor such as, for example, a compound of the invention.The invention further is directed to methods of inhibiting cancer cellgrowth, including processes of cellular proliferation, invasiveness, andmetastasis in biological systems. Methods include use of a compound ofthe invention as an inhibitor of cancer cell growth. Preferably, themethods are employed to inhibit or reduce cancer cell growth,invasiveness, metastasis, or tumor incidence in living animals, such asmammals. The compounds of the invention can be used, either alone or incombination with the use of IR or one or more chemotherapeutic agents,in treating cancer or inhibiting cancer cell growth. Methods of theinvention also are readily adaptable for use in assay systems, e.g.,assaying cancer cell growth and properties thereof, as well asidentifying compounds that affect cancer cell growth.

Tumors or neoplasms include growths of tissue cells in which themultiplication of the cells is uncontrolled and progressive. Some suchgrowths are benign, but others are termed “malignant” and can lead todeath of the organism. Malignant neoplasms or “cancers” aredistinguished from benign growths in that, in addition to exhibitingaggressive cellular proliferation, they can invade surrounding tissuesand metastasize. Moreover, malignant neoplasms are characterized in thatthey show a greater loss of differentiation (greater“dedifferentiation”) and their organization relative to one another andtheir surrounding tissues. This property is also called “anaplasia.”

Neoplasms treatable by the present invention also include solid tumors,i.e., carcinomas and sarcomas. Carcinomas include those malignantneoplasms derived from epithelial cells which infiltrate (invade) thesurrounding tissues and give rise to metastases. Adenocarcinomas arecarcinomas derived from glandular tissue, or from tissues which formrecognizable glandular structures. Another broad category of cancersincludes sarcomas, which are tumors whose cells are embedded in afibrillar or homogeneous substance like embryonic connective tissue. Theinvention also enables treatment of cancers of the myeloid or lymphoidsystems, including leukemias, lymphomas, and other cancers thattypically do not present as a tumor mass, but are distributed in thevascular or lymphoreticular systems.

DNA-PK activity can be associated with various forms of cancer in, forexample, adult and pediatric oncology, growth of solidtumors/malignancies, myxoid and round cell carcinoma, locally advancedtumors, metastatic cancer, human soft tissue sarcomas, including Ewing'ssarcoma, cancer metastases, including lymphatic metastases, squamouscell carcinoma, particularly of the head and neck, esophageal squamouscell carcinoma, oral carcinoma, blood cell malignancies, includingmultiple myeloma, leukemias, including acute lymphocytic leukemia, acutenonlymphocytic leukemia, chronic lymphocytic leukemia, chronicmyelocytic leukemia, and hairy cell leukemia, effusion lymphomas (bodycavity based lymphomas), thymic lymphoma lung cancer, including smallcell lung carcinoma, cutaneous T cell lymphoma, Hodgkin's lymphoma,non-Hodgkin's lymphoma, cancer of the adrenal cortex, ACTH-producingtumors, nonsmall cell cancers, breast cancer, including small cellcarcinoma and ductal carcinoma, gastrointestinal cancers, includingstomach cancer, colon cancer, colorectal cancer, polyps associated withcolorectal neoplasia, pancreatic cancer, liver cancer, urologicalcancers, including bladder cancer, including primary superficial bladdertumors, invasive transitional cell carcinoma of the bladder, andmuscle-invasive bladder cancer, prostate cancer, malignancies of thefemale genital tract, including ovarian carcinoma, primary peritonealepithelial neoplasms, cervical carcinoma, uterine endometrial cancers,vaginal cancer, cancer of the vulva, uterine cancer and solid tumors inthe ovarian follicle, malignancies of the male genital tract, includingtesticular cancer and penile cancer, kidney cancer, including renal cellcarcinoma, brain cancer, including intrinsic brain tumors,neuroblastoma, astrocytic brain tumors, gliomas, metastatic tumor cellinvasion in the central nervous system, bone cancers, including osteomasand osteosarcomas, skin cancers, including malignant melanoma, tumorprogression of human skin keratinocytes, squamous cell cancer, thyroidcancer, retinoblastoma, neuroblastoma, peritoneal effusion, malignantpleural effusion, mesothelioma, Wilms's tumors, gall bladder cancer,trophoblastic neoplasms, hemangiopericytoma, and Kaposi's sarcoma.Methods to potentiate treatment of these and other forms of cancer areembraced by the invention.

The invention provides a method of inhibiting DNA-PK activity in abiological sample that includes contacting the biological sample with acompound or composition of the invention. The term “biological sample,”as used herein, means a sample outside a living organism and includes,without limitation, cell cultures or extracts thereof; biopsied materialobtained from a mammal or extracts thereof; and blood, saliva, urine,feces, semen, tears, or other body fluids or extracts thereof.Inhibition of kinase activity, particularly DNA-PK activity, in abiological sample is useful for a variety of purposes known to one ofskill in the art. Examples of such purposes include, but are not limitedto, biological specimen storage and biological assays. In oneembodiment, the method of inhibiting DNA-PK activity in a biologicalsample is limited to non-therapeutic methods.

Preparation of Compounds of the Invention

As used herein, all abbreviations, symbols and conventions areconsistent with those used in the contemporary scientific literature.See, e.g., Janet S. Dodd, ed., The ACS Style Guide: A Manual for Authorsand Editors, 2nd Ed., Washington, D.C.: American Chemical Society, 1997.The following definitions describe terms and abbreviations used herein:

-   BPin pinacol boronate ester-   Brine a saturated NaCl solution in water-   DCM dichloromethane-   DIAD diisopropylazodicarboxylate-   DIEA diisopropylethylamine-   DMA dimethylacetamide-   DMF dimethylformamide-   DMSO dimethylsulfoxide-   DTT dithiothreitol-   ESMS electrospray mass spectrometry-   Et₂O ethyl ether-   EtOAc ethyl acetate-   EtOH ethyl alcohol-   HEPES 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid-   HPLC high performance liquid chromatography-   IPA isopropanol-   LAH lithium aluminum hydride-   LC-MS liquid chromatography-mass spectrometry-   LDA lithium diisoproylethylamide-   Me methyl-   MeOH methanol-   MsCl methanesulfonyl chloride-   MTBE methyl t-butyl ether-   NMP N-methylpyrrolidine-   Pd₂(dba)₃ tris(dibenzylideneacetone)dipalladium(O)-   Pd(dppf)Cl₂ 1,1′ bis(diphenylphosphino)-ferrocene dichloro-palladium-   PG protecting group-   Ph phenyl-   (rac)-BINAP racemic 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl-   RockPhos    di-tert-butyl(2′,4′,6′-triisopropyl-3,6-dimethoxy-[1,1′-biphenyl]-2-yl)phosphine-   RT or rt room temperature-   SFC supercritical fluid chromatography-   SPhos 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl-   TBAI tetrabutylammonium iodide-   tBu tertiary butyl-   THF tetrahydrofuran-   TEA triethylamine-   TMEDA tetramethylethylenediamine-   VPhos    [3-(2-dicyclohexylphosphanylphenyl)-2,4-dimethoxy-phenyl]sulfonyloxysodium

GENERAL SYNTHETIC PROCEDURES

In general, the compounds of this invention may be prepared by methodsdescribed herein or by other methods known to those skilled in the art.

Example 1 General Preparation of the Compounds of Formula G

Compounds of formula I, wherein X¹ is NH (i.e., compounds of formulaI-A), can be prepared as outlined below in Scheme 1. Accordingly, asshown in step 1-i of Scheme 1, heteroaryl compounds of formula A can bereacted with morpholine or a morpholine analog by heating the mixture ina polar, non-protic solvent to produce compounds of formula B. Utilizinga palladium-catalyzed, phosphine ligand-assisted Buchwald/Hartwig-typecoupling, as shown in step 1-ii of Scheme 1, a compound of formula B canbe reacted with aminocyclohexanes of formula C to produce compounds offormula D, wherein R¹ and R² are as described elsewhere herein. In oneexample, when monoprotected meso cyclohexane-1,4-diamines of formula Eare prepared, removal of the protecting group forms compounds of formulaF, as shown in step 1-iii of Scheme 1. The resulting free amine can thenbe reacted with various moieties having groups reactive towards amines(e.g., R^(1a)-L, where L is a leaving group such as chloro, bromo, iodo,toluenesulfonate, methanesulfonate, or trifluoromethanesulfonate; orwhere L is a reactive carbonyl-containing moiety such as an active esteror an isocyanato group) to produce a compound of formula G, as shown instep 1-iv of Scheme 1.

Example 2 General Preparation of the Compounds of Formula M, N, R, and S

Compounds of formula I, wherein X¹ is O can be prepared as outlinedbelow in Schemes 2a and 2b. Accordingly, as shown in step 2-i of Scheme2a, the hydroxyl group of heteroaryl compounds of formula H can beprotected to produce compounds of formula J, which can then be reactedwith morpholine or a morpholine analog by heating the mixture in apolar, non-protic solvent to produce compounds of formula K afterremoval of the protecting group, as shown in steps 2-ii and 2-iii ofScheme 2a. Subsequently, as shown in step 2-iv of Scheme 2a, a compoundof formula K can be reacted with a compound of formula L underconditions sufficient to affect the SN2 displacement of its leavinggroup (e.g., where L is a leaving group such as chloro, bromo, iodo,toluenesulfonate, methanesulfonate, or trifluoromethanesulfonate) toproduce a compound of formula M or formula M, depending on whether R¹ orR² is hydrogen. In those instances when R¹ or R² are protected nitrogenor oxygen moieties, compounds of the invention can be produced byremoval of the protecting group and subsequent synthetic manipulation ofthe resulting free amine/alcohol.

Alternatively, as shown in Scheme 2b, the hydroxyl group of a compoundof formula O can be reacted with a compound of formula L to produce afused bicycloheteroaryl bromide of formula P, which can subsequently bereacted with morpholine or a morpholine analog to produce a compound offormula M or formula N.

Alternatively, as shown in Scheme 2c, compounds of the invention inwhich Ring B is a dihydropyran ring can be prepared by reactingcompounds of formula Q with dialkyl (3,6-dihydro-2H-pyran-4-yl)boronatesto produce compounds of formula R. Compounds of formula R can then besubsequently reduced to form compounds of formula S.

Example 3 Preparation of ethyl(4-((7-morpholinoquinoxalin-5-yl)amino)cyclohexyl)carbamate (Compound 6)andN¹-(7-morpholinoquinoxalin-5-yl)-N⁴-(pyrimidin-2-yl)cyclohexane-1,4-diamine(Compound 18)

As shown in step 3-i of Scheme 3, to a solution of3-bromo-5-fluoro-benzene-1,2-diamine (compound 1001, 1.11 g, 5.41 mmol)in methanol (11 mL) was added oxaldehyde (1.57 mL of 40% w/v, 10.8mmol). The reaction mixture was stirred at room temperature undernitrogen. After 2 hours a yellow solid precipitated. The reactionmixture was diluted with water (20 mL), stirred an additional 5 minutes,filtered, and the collected solid dried under high vacuum to produce5-bromo-7-fluoroquinoxaline (compound 1002, 868 mg, 70.6% yield): ¹H-NMR(300 MHz, DMSO-d₆) δ 9.06 (s, 2H), 8.36 (dd, J=8.5, 2.7 Hz, 1H), 8.00(dd, J=9.2, 2.7 Hz, 1H); ESMS (M+H⁺)=227.14.

As shown in step 3-ii of Scheme 3, to a solution of5-bromo-7-fluoroquinoxaline (4.5 g, 19.8 mmol) in NMP (67.5 mL) wasadded morpholine (3.1 mL, 35.6 mmol). The reaction mixture was heated to140° C. and stirred for 15 hours. After cooling, the mixture was pouredinto water (200 mL), extracted with ethyl acetate (2×100 mL), dried overmagnesium sulfate, filtered, evaporated under reduced pressure, andpurified by medium pressure silica gel chromatography (10 to 80%EtOAc/hexanes gradient) to provide 4-(8-bromoquinoxalin-6-yl)morpholine(compound 1003, 3.86 g, 66% yield) as a yellow solid: ¹H-NMR (400 MHz,DMSO-d₆) δ 8.82 (d, J=1.6 Hz, 1H), 8.73 (d, J=1.6 Hz, 1H), 8.12 (d,J=2.5 Hz, 1H), 7.27 (d, J=2.4 Hz, 1H), 3.87-3.69 (m, 4H), 3.44-3.34 (m,4H); ESMS (M+H⁺)=227.14.

As shown in step 3-iii of Scheme 3, a mixture of4-(8-bromoquinoxalin-6-yl)morpholine (1.57 g, 5.34 mmol),tert-butyl-N-(4-aminocyclohexyl)carbamate (1.37 g, 6.40 mmol),(rac)-BINAP (664 mg, 1.07 mmol), cesium carbonate (5.22 g, 16.0 mmol),and Pd₂(dba)₃ (489 mg, 0.534 mmol) in toluene (50 mL) was heated at 100°C. for 12 hours. After cooling, the mixture was diluted with ethylacetate (150 mL) and water (25 mL), then filtered through diatomaceousearth which was subsequently washed with ethyl acetate. The combinedorganics were washed with brine, dried over sodium sulfate, concentratedunder reduced pressure, and purified by medium pressure silica gelchromatography (0 to 60% EtOAc/hexanes gradient) to providetert-butyl(-4-((7-morpholinoquinoxalin-5-yl)amino)cyclohexyl)carbamate(compound 1004, 1.83 g, 83.2% yield): ¹H-NMR (300 MHz, CDCl₃) δ 8.65 (d,J=2.0 Hz, 1H), 8.35 (d, J=2.0 Hz, 1H), 6.60 (d, J=2.4 Hz, 1H), 6.34 (d,J=2.4 Hz, 1H), 6.11 (d, J=7.8 Hz, 1H), 4.60 (s, 1H), 3.97-3.86 (m, 4H),3.67 (s, 2H), 3.41-3.25 (m, 4H), 1.85 (d, J=3.0 Hz, 5H), 1.74-1.57 (m,3H), 1.45 (s, 9H).

As shown in step 3-iv of Scheme 3, to a solution of tent-butyl(-4-((7-morpholinoquinoxalin-5-yl)amino)cyclohexyl)carbamate (900 mg,2.00 mmol) in dichloromethane (16 mL) was added trifluoroacetic acid (3mL, 38.9 mmol). The resulting black reaction mixture was stirred underan atmosphere of nitrogen at room temperature for 2 hours. Saturatedaqueous sodium bicarbonate (150 mL) was added slowly until the colorturned from black to orange. The mixture was extracted withdichloromethane (2×100 mL) and the combined organics washed with brine(50 mL), dried over sodium sulfate, and concentrated under reducedpressure toprovide-N¹-(7-morpholinoquinoxalin-5-yl)cyclohexane-1,4-diamine,trifluoroacetate (compound 1005): ¹H NMR (300 MHz, CDCl₃) δ 8.64 (d,J=1.9 Hz, 1H), 8.36 (d, J=1.9 Hz, 1H), 6.59 (d, J=2.3 Hz, 1H), 6.34 (d,J=2.3 Hz, 1H), 6.20 (d, J=7.9 Hz, 1H), 3.95-3.84 (m, 4H), 3.69 (s, 1H),3.41-3.25 (m, 4H), 2.93 (d, J=8.9 Hz, 1H), 2.09-1.87 (m, 2H), 1.90-1.68(m, 6H), 1.58 (dd, J=11.2, 8.7 Hz, 2H); ESMS (M+H⁺)=328.34. Thiscompound was used as is without further purification.

As shown in step 3-v of Scheme 3, to solution ofN¹-(7-morpholinoquinoxalin-5-yl)cyclohexane-1,4-diamine (25 mg, 0.07mmol) and diisopropylethylamine (18.0 mg, 24.3 μL, 0.14 mmol) indichloromethane (750 μL) was added ethyl chloroformate (11.4 mg, 10.0μL, 0.105 mmol). The reaction mixture was stirred for 12 hours, dilutedwith dichloromethane (10 mL), washed with saturated aqueous sodiumbicarbonate (5 mL), dried over sodium sulfate, and concentrated underreduced pressure. The resulting residue was purified by HPLC preparativechromatography using a 10-90% acetonitrile/water (0.1% TFA) gradient aseluant to provide ethyl(4-((7-morpholinoquinoxalin-5-yl)amino)cyclohexyl)carbamate (compound 6,14 mg, 50% yield): ¹H-NMR (300 MHz, CDCl₃) δ 8.65 (d, J=2.0 Hz, 1H),8.36 (d, J=2.0 Hz, 1H), 6.61 (d, J=2.4 Hz, 1H), 6.35 (d, J=2.4 Hz, 1H),6.10 (d, J=7.6 Hz, 1H), 4.72 (s, 1H), 4.12 (q, J=7.0 Hz, 2H), 3.96-3.82(m, 4H), 3.68 (s, 2H), 3.42-3.23 (m, 4H), 1.93-1.78 (m, 6H), 1.69 (dd,J=15.0, 6.3 Hz, 2H), 1.25 (t, J=7.1 Hz, 3H); ESMS (M+H⁺)=400.17.

As shown in step 3-vi of Scheme 3, A mixture ofN¹-(7-morpholinoquinoxalin-5-yl)cyclohexane-1,4-diamine (185 mg, 0.56mmol), 2-bromopyrimidine (93 mg, 0.58 mmol), and triethylamine (143 mg,197 μL, 1.41 mmol) in 1-methylpyrrolidin-2-one (3 mL) was heated to 130°C. and stirred for 15 hours. After cooling to room temperature, themixture was diluted with ethyl acetate (70 mL) and methyl tert-butylether (20 mL), washed with water (3×20 mL), washed with brine (15 mL),dried over sodium sulfate, concentrated under reduced pressure, andpurified by medium pressure silica gel chromatography (10 to 100%EtOAc/hexanes gradient) to provideN¹-(7-morpholinoquinoxalin-5-yl)-N⁴-(pyrimidin-2-yl)cyclohexane-1,4-diamine(compound 18, 102 mg, 45% yield): ¹H-NMR (300 MHz, CDCl₃) δ 8.65 (d,J=2.0 Hz, 1H), 8.37 (d, J=2.0 Hz, 1H), 8.27 (d, J=4.8 Hz, 2H), 6.60 (d,J=2.4 Hz, 1H), 6.51 (t, J=4.8 Hz, 1H), 6.36 (d, J=2.4 Hz, 1H), 6.15 (d,J=7.8 Hz, 1H), 5.20 (d, J=7.7 Hz, 1H), 4.04 (d, J=7.9 Hz, 1H), 3.96-3.82(m, 4H), 3.70 (s, 1H), 3.39-3.24 (m, 4H), 1.94 (dd, J=13.7, 4.4 Hz, 6H),1.78 (dt, J=28.8, 16.1 Hz, 2H); ESMS (M+H⁺)=328.34.

Example 4 Preparation of1-(4-((7-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)quinoxalin-5-yl)amino)cyclohexyl)-3-ethylurea(Compound 22)\

As shown in step 4-i of Scheme 4, to a solution of5-bromo-7-fluoroquinoxaline (compound 1002, 150 mg, 0.66 mmol) in NMP(2.3 mL) was added 8-oxa-3-azabicyclo[3.2.1]octane (178 mg, 1.2 mmol) atRT. The reaction mixture was sealed in a microwave vial and heated at180° C. for 20 minutes. Afte cooling to RT and pouring into water, theaqueous phase was extracted with EtOAc (3×). The combined extracts weredried over MgSO₄, filtered, concentrated under reduced pressure, andpurified by medium pressure silica gel chromatography (0 to 100%EtOAc/hexanes gradient) to provide3-(8-bromoquinoxalin-6-yl)-8-oxa-3-azabicyclo[3.2.1]octane (compound1006, 87 mg, 41% yield) as a dark orange oil: ESMS (M+H⁺)=320.07.

As shown in step 4-ii of Scheme 4, a degassed solution of3-(8-bromoquinoxalin-6-yl)-8-oxa-3-azabicyclo[3.2.1]octane (261 mg,0.815 mmol), tent-butyl N-(4-aminocyclohexyl)carbamate (210 mg, 0.98mmol), rac-BINAP (102 mg, 0.163 mmol), Cs₂CO₃ (797 mg, 2.45 mmol), andPd₂(dba)₃ (75 mg, 0.0815 mmol) in toluene (10.5 mL) was heated at 100°C. (oil bath temp) in a sealed microwave tube for 15 hours. Aftercooling, the mixture was applied directly to a chromatography column andpurified by medium pressure silica gel chromatography (0 to 100%EtOAc/hexanes gradient) to afford tent-butyl(4-((7-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)quinoxalin-5-yl)amino)cyclohexyl)carbamate(compound 1007, 141 mg, 36% yield) as a white solid: ¹H-NMR (400 MHz,CDCl₃) d 8.49 (s, 1H), 8.23 (d, J=1.5 Hz, 1H), 6.48 (s, 1H), 6.18 (d,J=1.9 Hz, 1H), 6.06 (s, 1H), 4.52 (s, 1H), 4.47 (s, 2H), 3.60 (s, 2H),3.45 (d, J=11.6 Hz, 2H), 3.14-3.12 (m, 2H), 1.96-1.84 (m, 4H), 1.79 (s,5H), 1.54 (s, 3H) and 1.38 (s, 9H) ppm; ESMS (M+H⁺)=453.96.

As shown in step 4-iii of Scheme 4, to a solution of compound 1007 (141mg, 0.295 mmol) in CH₂Cl₂ (2.5 mL) was added TFA (656 mg, 443 μL, 5.75mmol) at RT. The resulting black solution was stirred for 2 hours andthen the reaction was quenched by the addition of saturated NaHCO₃ untilthe black color gradually turned into an orange color. The reactionmixture was extracted with CH₂Cl₂ (3×) and the combined organic extractswere dried over Na₂SO₄ and evaporated to dryness to provideN¹-(7-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)quinoxalin-5-yl)cyclohexane-1,4-diamine,trifluoroacetate (compound 1008): ESMS (M+H⁺)=354.20. This material wasused in subsequent reactions without any further purification.

As shown in step 4-iv of Scheme 4, to a solution of compound 1008 (45mg, 0.071 mmol) and DIEA (36.5 mg, 49.0 μL, 0.28 mmol) in CH₂Cl₂ (1.4mL) was added ethyl isocyanate (20 mg, 0.28 mmol) at RT. The solutionwas stirred at this temperature for 15 hours and then applied directlyto a chromatography column and purified by medium pressure silica gelchromatograph (0 to 100% EtOAc/hexanes gradient) to afford1-(4-((7-(8-oxa-3-azabicyclo[3.2.1]octan-3-yl)quinoxalin-5-yl)amino)cyclohexyl)-3-ethylurea(compound 22, 8 mg, 27% yield) as a white solid: ¹H-NMR (400 MHz, CDCl₃)δ 8.54 (s, 1H), 8.22 (s, 1H), 6.43 (s, 1H), 6.19 (s, 1H), 6.02 (s, 1H),4.47 (s, 2H), 4.38 (d, J=5.2 Hz, 1H), 4.28 (s, 1H), 3.74 (s, 1H), 3.60(s, 1H), 3.42 (s, 4H), 3.14-3.09 (m, 4H), 2.05-1.87 (m, 3H), 1.79 (s,3H), 1.55 (d, J=7.1 Hz, 2H) and 1.21-1.05 (m, 5H) ppm; ESMS(M+H⁺)=425.35.

Example 5 Preparation of N¹-(6-morpholinobenzo[c][1,2,5]oxadiazol-4-yl)-N⁴-(pyrimidin-2-yl)cyclohexane-1,4-diamine(Compound 23)

As shown in step 5-i of Scheme 5, a mixture of tent-butyl((cis)-4-aminocyclohexyl)carbamate (compound 1009, 490 mg, 2.3 mmol),2-chloropyrimidine (262 mg, 2.3 mmol) and TEA (463 mg, 6374, 4.6 mmol)in DMF (10 mL) was subjected to microwave irradiation for 20 minutes at150° C. The reaction mixture was diluted with EtOAc, washed with H₂O,dried over Na₂SO₄, concentrated under reduced pressure, and purified bymedium pressure silica gel chromatography (0 to 50% EtOAc/hexanesgradient) to provide tert-butyl((cis)-4-(pyrimidin-2-ylamino)cyclohexyl)carbamate (compound 1010) as awhite solid: ¹H-NMR (300 MHz, CDCl₃) δ 8.28 (d, J=4.8 Hz, 2H), 6.53 (t,J=4.8 Hz, 1H), 5.12 (s, 1H), 4.56 (s, 1H), 3.99 (dq, J=7.0, 3.5 Hz, 1H),3.65 (s, 1H), 1.83 (tq, J=10.2, 3.6 Hz, 5H), 1.66 (s, 8H), 8.13-7.91 (m,3H), 1.47 (s, 9H).

As shown in step 5-ii of Scheme 5, HCl (3 mL, 4M in THF, 12 mmol) wasadded to compound 1010. The mixture was stirred for 30 min andconcentrated under reduced pressure to produce(cis)-N¹-(pyrimidin-2-yl)cyclohexane-1,4-diamine hydrochloride (compound1011). This material was used in subsequent reactions as is withoutfurther purification.

As shown in step 5-iii of Scheme 5, a mixture of4-bromo-6-morpholinobenzo[c][1,2,5]oxadiazole (compound 1012, 147 mg,0.5 mmol), (cis)-N¹-(pyrimidin-2-yl)cyclohexane-1,4-diaminehydrochloride (120 mg, 0.6 mmol), (rac)-BINAP (32 mg, 0.05 mmol),Pd₂(dba)₃ (24 mg, 0.026 mmol), and cesium carbonate (506 mg, 1.55 mmol)in toluene (5 mL) was flushed with nitrogen gas and stirred overnight at90° C. under an atmosphere of nitrogen. The mixture was filtered thougha layer of diatomaceous earth, concentrated under reduced pressure, andpurified by medium pressure silica gel chromatography (0 to 80%EtOAc/hexanes gradient) to provide(cis)-N¹-(6-morpholinobenzo[c][1,2,5]oxadiazol-4-yl)-N⁴-(pyrimidin-2-yl)cyclohexane-1,4-diamine(compound 23) as an orange solid: ¹H-NMR (300 MHz, CDCl₃) δ 8.20 (d,J=4.9 Hz, 2H), 6.46 (t, J=4.8 Hz, 1H), 6.05 (d, J=1.6 Hz, 1H), 5.82 (s,1H), 5.24 (s, 1H), 4.82 (d, J=7.0 Hz, 1H), 3.98 (s, 1H), 3.85-3.72 (m,4H), 3.60 (s, 1H), 3.23-3.06 (m, 4H), 1.95-1.62 (m, 8H).

Example 6 Preparation of5-methoxy-N-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(Compound 134)

As shown in step 6-i of Scheme 6, to a mixture of5-bromo-2-fluoro-pyrimidine (1 g, 5.651 mmol) in iPrOH (10 mL) was addedTEA (1.143 g, 1.574 mL, 11.30 mmol) and trans-4-aminocyclohexan-1-ol(650.8 mg, 5.651 mmol). The mixture was microwaved for 20 min at 150°C., concentrated under reduced pressure, diluted with EtOAc , washedwith water, and dried over Na₂SO₄. After removal of the volatiles underreduced pressure, the residue was purified by medium pressure silica gelchromatography (0-80% EtOAc/hexanes gradient) to provide(trans)-4-((5-bromopyrimidin-2-yl)amino)cyclohexanol (compound 1013, 1.2g): ¹H-NMR (300 MHz, CDCl₃) δ 8.28 (s, 2H), 5.03 (d, J=8.1 Hz, 1H),3.91-3.49 (m, 2H), 2.31-1.90 (m, 4H), 1.56-1.19 (m, 4H).

As shown in step 6-ii of Scheme 6, to compound 1013 (1.2 g, 4.41 mmol)in DCM (20 mL) was added TEA (1.134 g, 1.84 mL, 13.2 mmol) and MsCl (505mg, 341 μL, 4.41 mmol). The reaction mixture was stirred for 1 hour,concentrated under reduced pressure, and purified by medium pressuresilica gel chromatography (0 to 80% EtOAc/hexanes gradient) to providetrans-4-((5-bromopyrimidin-2-yl)amino)cyclohexyl methanesulfonate(compound 1014): ¹H-NMR (300 MHz, CDCl₃) δ 8.29 (s, 2H), 5.03 (d, J=7.8Hz, 1H), 4.70 (tt, J=10.6, 3.9 Hz, 1H), 3.80 (dtt, J=11.2, 7.6, 3.7 Hz,1H), 3.04 (s, 3H), 2.30-2.12 (m, 4H), 1.93-1.69 (m, 2H), 1.51-1.33 (m,2H).

As shown in step 6-iii of Scheme 6, to a solution of2-amino-3-nitrophenol (5.00 g, 32.4 mmol) in dioxane (50 mL) was addedbromine (6.22 g, 2.01 mL, 38.9 mmol). The mixture was stirred for 2hours and a precipitate formed, which was collected and washed withdioxane and ether. The resulting yellow solid treated with a saturatedNaHCO₃ solution, which was extracted with EtOAc (3×). The combinedorganics were dried over Na₂SO₄, filtered, and concentrated underreduced pressure to yield 2-amino-5-bromo-3-nitrophenol (compound 1015)as a brown solid. This material was carried on as is in subsequentreactions without futher purification.

As shown in step 6-iv of Scheme 6, to a solution of2-amino-5-bromo-3-nitrophenol (7.5 g, 31.8 mmol) in ethyl acetate (60mL) was added Raney nickel™ (1.90 g, 214 μL, 32.4 mmol) and the reactionmixture was shaken for 2 hours under an atmosphere of H₂ at 30 p.s.i.After filtering and drying over Na₂SO₄, the mixture was concentratedunder reduced pressure to provide 2,3-diamino-5-bromophenol (compound1016), which was used as is in subsequent reactions without futherpurification.

As shown in step 6-v of Scheme 6, 2,3-diamino-5-bromophenol (6.0 g, 29.5mmol) was dissolved in methanol and to this solution was added glyoxal(3.77 g, 2.98 mL, 64.9 mmol) and stirred overnight. The reaction mixturewas concentrated under reduced pressure to a minimum volume and theresulting tan solid collected by filtration and dried under high vacuumto produce 7-bromoquinoxalin-5-ol (compound 1017), which was used as isin subsequent reactions without futher purification.

As shown in step 6-vi of Scheme 6, a solution of 7-bromoquinoxalin-5-ol(2.0 g, 8.89 mmol) in DCM (20 mL) was added imidazole (1.82 g, 26.7mmol) and tert-butyldimethylsilyl chloride (1.34 g, 1.65 mL, 8.89 mmol).The reaction mixture was stirred overnight at RT, concentrated underreduced pressure, and purified by medium pressure silica gelchromatography (0 to 20% EtOAc/hexanes gradient) to provide7-bromo-5-((tert-butyldimethylsilyl)oxy)quinoxaline (compound 1018) as acolorless oil: ¹H-NMR (300 MHz, CDCL₃) δ 8.69 (q, J=1.8 Hz, 2H), 7.80(d, J=2.1 Hz, 1H), 7.22 (d, J=2.1 Hz, 1H), 0.96 (s, 9H), 0.81 (s, 7H).

As shown in step 6-vii of Scheme 6, a mixture of7-bromo-5-((tert-butyldimethylsilyl)oxy)quinoxaline (700 mg, 2.06 mmol),morpholine (270 mg, 270 μL, 3.09 mmol), Pd₂(dba)₃ (94.50 mg, 0.1032mmol), (rac)-BINAP (129 mg, 0.206 mmol), cesium carbonate (2.02 g, 6.19mmol) in toluene (7 mL) was flushed with nitrogen for 10 minutes. Themixture was then heated overnight at 100° C. After cooling, the reactionmixture was diluted with EtOAc, filtered through a layer of diatomaceousearth, concentrated under reduced pressure, and purified by mediumpressure silica gel chromatography (0 to 30% EtOAc/hexanes gradient) toprovide 7-morpholinoquinoxalin-5-ol. This compound (450 mg, 1.3 mmol)was dissolved in THF (20 mL) and tetra-n-butylammonium fluoride (539 mg,2.06 mmol) was added. The reaction mixture was stirred for 0.5 hour,concentrated under reduced pressure, and purified by medium pressuresilica gel chromatography (0 to 100% EtOAc/hexanes gradient) to provide7-morpholinoquinoxalin-5-ol (compound 1019) as a yellow solid: ¹H-NMR(300 MHz, CDCl₃) δ 8.75 (d, J=2.0 Hz, 1H), 8.46 (d, J=2.0 Hz, 1H), 7.70(d, J=41.8 Hz, 1H), 7.01 (d, J=2.6 Hz, 1H), 6.89 (d, J=2.5 Hz, 1H),4.12-3.78 (m, 4H), 3.51-3.24 (m, 4H).

As shown in step 6-viii of Scheme 6, a solution of7-morpholinoquinoxalin-5-ol (100 mg, 0.432 mmol),(trans)-4-((5-bromopyrimidin-2-yl)amino)cyclohexyl methanesulfonate(compound 1014, 303 mg, 0.865 mmol), and CsCO₃ (282 mg, 0.865 mmol) indioxane (1.0 mL was stirred for 16 hours at 105° C. After cooling, thereaction mixture was diluted with EtOAc, filtered through diatomaceousearth, concentrated under reduced pressure, and purified by mediumpressure silica gel chromatography (0 to 5% MeOH/DCM gradient) toproduce5-bromo-N-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(compound 1020, 110 mg) as a yellow foam: ¹H-NMR (400 MHz, CDCl₃) δ 8.70(d, J=2.0 Hz, 1H), 8.64 (d, J=1.9 Hz, 1H), 8.29 (s, 2H), 6.98 (d, J=2.5Hz, 1H), 6.92 (d, J=2.5 Hz, 1H), 5.29 (d, J=8.3 Hz, 1H), 4.81 (s, 1H),4.04-3.84 (m, 4H), 3.42-3.31 (m, 4H), 2.22 (s, 2H), 1.92 (d, J=4.9 Hz,6H).

As shown in step 6-ix of Scheme 6, to a mixture5-bromo-N-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(75 mg, 0.155 mmol), cesium carbonate (101 mg, 0.309 mmol) ,allylpalladium(II) chloride dimer (0.28 mg, 0.0015 mmol), RockPhos (2.17mg, 0.0046 mmol) and MeOH (9.9 mg, 12.5 μL, 0.31 mmol) in toluene (2 mL)was flushed with nitrogen gas and heated to 100° C. for 18 hours. Thereaction mixture was iluted with EtOAc, filtered though a layer ofdiatomaceous earth, and concentrated under reduced pressure.Purification by medium pressure silica gel chromatography (0-8% MeOH/DCMgradient) yielded5-methoxy-N-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(compound 134, 43 mg): ¹H-NMR (300 MHz, CDCl₃) δ 8.70 (d, J=1.9 Hz, 1H),8.63 (d, J=1.9 Hz, 1H), 8.07 (s, 2H), 6.96 (d, J=2.5 Hz, 1H), 6.92 (d,J=2.5 Hz, 1H), 5.01 (d, J=8.1 Hz, 1H), 4.80 (q, J=5.6, 4.2 Hz, 1H),4.03-3.87 (m, 5H), 3.80 (s, 3H), 3.42-3.27 (m, 4H), 2.29-2.10 (m, 2H),1.99-1.82 (m, 6H).

Example 7 Preparation of4-(8-(((trans)-4-(pyrimidin-2-yloxy)cyclohexyl)oxy)quinoxalin-6-yl)morpholine(Compound 34) and4-(8-(((cis)-4-(pyrimidin-2-loxy)cyclohexyl)oxy)-quinoxalin-6-yl)morpholine(Compound 42)

As shown in step 7-i of Scheme 7, to a solution of1,4-dioxaspiro[4.5]decan-8-ol (compound 1021, 1.0 g, 6.32 mmol) in DMF(10 mL) was added NaH (370 mg, 9.25 mmol). The reaction mixture wasstirred for 20 minutes before the addition of 2-chloropyrimidine (869mg, 7.59 mmol). The mixture was stirred for 30 minute at RT and thenheated to 100° C. for 9 hours. After cooling, the mixture was dilutedwith EtOAc, washed with H₂O, dried over Na₂SO₄, concentrated underreduced pressure, and purified by medium pressure silica gelchromatography (0-40% EtOAc/hexanes) to produce2-(1,4-dioxaspiro[4.5]decan-8-yloxy)pyrimidine (compound 1022) as acolorless oil: ¹H NMR (300 MHz, Chloroform-d) δ 8.52 (d, J=4.8 Hz, 2H),6.92 (t, J=4.8 Hz, 1H), 5.15 (ddd, J=10.7, 6.5, 4.2 Hz, 1H), 4.05-3.87(m, 4H), 2.14-1.85 (m, 6H), 1.79-1.65 (m, 2H); ESMS (M+H⁺)=237.12.

As shown in step 7-ii of Scheme 7, to2-(1,4-dioxaspiro[4.5]decan-8-yloxy)pyrimidine (620 mg, 2.624 mmol) wasadded HCl (4.0 mL of 6 M, 8.86 mmol) and the reaction mixture wasstirred for 2 hours. The pH of the mixture was neutralized with withsat. NaHCO₃(aq) and the mixture was concentrated under reduced pressureas a methanol azeotrope. To the residue was added DCM (30 mL) to producea precipitate, followed by stirring for an additional 20 minutes. Thesolids were filtered off and the mother liquor was concentrated underreduced pressure. The resulting residue was dissolved in methanol andsodium borohydride (151 mg, 3.99 mmol) was added as a solid. The mixturewas stirred for 1 hour and the reaction quenched with HCl (6M, 0.70 mL).Stirring was continued until gas evolution ceased. The pH of the mixturewas adjusted to about 8 with 1N sodium hydroxide and extracted withEtOAc (20 mL). The organics were dried over sodium sulfate andconcentrated under reduced pressure to produce4-(pyrimidin-2-yloxy)cyclohexanol (compound 1023, 248 mg, 64% yield) asa mixture of (cis)- and (trans)-isomers. A 12 mg aliquot of the samplewas purified via HPLC preperative reversed-phase chromatography (10-90%CH₃CN/water gradient containing 0.1% TFA) to separate the isomers:(trans)-4-pyrimidin-2-yloxycyclohexanol-¹H NMR (300 MHz, Chloroform-d) δ8.54 (d, J=4.8 Hz, 2H), 6.95 (t, J=4.8 Hz, 1H), 5.05 (tt, J=9.4, 4.0 Hz,1H), 3.91-3.75 (m, 1H), 2.26-1.99 (m, 4H), 1.76-1.41 (m, 4H); ESMS(M+H⁺)=195.07, (cis)-4-pyrimidin-2-yloxycyclohexanol-¹H NMR (300 MHz,Chloroform-d) δ 8.62 (d, J=4.9 Hz, 2H), 7.04 (t, J=4.9 Hz, 1H), 5.21(tt, J=5.3, 2.6 Hz, 1H), 4.56 (s, 1H), 3.85 (p, J=5.9 Hz, 1H), 2.17-2.02(m, 2H), 1.88-1.67 (m, 6H); ESMS (M+H⁺)=195.07. The remaining materialwas used in subsequent reactions as the cis/trans mixture.

As shown in step 7-iii of Scheme 7, to a solution of a cis/trans mixtureof 4-pyrimidin-2-yloxycyclohexanol (244 mg, 1.256 mmol) andtriethylamine (350 μL, 2.51 mmol) in dichloromethane (5 mL) was addedmethane sulfonyl chloride (145 μL, 1.87 mmol). The reaction mixture wasstirred for 2 hours, concentrated under reduced pressure, and purifiedby medium pressure silica gel chromatography (0-20%EtOAc/dichloromethane gradient) to provide4-pyrimidin-2-yloxycyclohexyl) methanesulfonate (compound 1024, 239 mg,70% yield) as a mixture of cis/trans isomers: ¹H NMR (300 MHz,Chloroform-d) δ 8.51 (d, J=4.8 Hz, 2H), 6.93 (t, J=4.8 Hz, 1H), 5.13(dq, J=9.9, 3.0 Hz, 1H), 4.87 (p, J=3.8 Hz, 1H), 3.04 (d, J=2.4 Hz, 3H),2.28-1.99 (m, 4H), 1.99-1.74 (m, 4H); ESMS (M+H⁺)=273.52.

As shown in step 7-iv of Scheme 7, a mixture of(4-pyrimidin-2-yloxycyclohexyl) methanesulfonate (105 mg, 0.386 mmol),7-morpholinoquinoxalin-5-ol (178.3 mg, 0.7712 mmol), and Cs₂CO₃ (125.6mg, 0.3856 mmol) in dioxane (1.5 mL) was sealed in a 5 mL microwave tubeand heated to 110° C. for 14 hours using an oil bath. The reactionmixture was cooled to room temperature, diluted with EtOAc, and filteredthrough diatomaceous earth which was subsequently washed with ethylacetate. The filtrate was concentrated under reduced pressure and theresidue purified via preparative reversed-phase HPLC (10-90% CH₃CN/watergradient containing 0.1% TFA). Fractions containing a mixture of cis andtrans isomers were further purified via SFC using a chiral OJ column andeluting with 40% MeOH in CO₂ to provide 21 mg of4-(8-(((trans)-4-(pyrimidin-2-yloxy)cyclohexyl)oxy)quinoxalin-6-yl)morpholine(compound 34): ¹H NMR (300 MHz, Chloroform-d) δ 8.69 (dd, J=3.4, 1.9 Hz,1H), 8.62 (dd, J=3.6, 1.9 Hz, 1H), 8.51 (dd, J=4.8, 2.2 Hz, 2H),7.01-6.83 (m, 3H), 5.18 (tt, J=7.0, 3.4 Hz, 1H), 4.79 (tt, J=6.9, 3.1Hz, 1H), 4.00-3.85 (m, 4H), 3.34 (dq, J=4.8, 2.6 Hz, 4H), 2.44-2.16 (m,4H), 1.92 (tdd, J=16.4, 7.7, 2.8 Hz, 4H); ESMS (M+H⁺)=408.56, and 22 mgof4-(8-(((cis)-4-(pyrimidin-2-yloxy)cyclohexyl)oxy)-quinoxalin-6-yl)morpholine(compound 42): ¹H NMR (300 MHz, Chloroform-d) δ 8.70 (d, J=1.9 Hz, 1H),8.63 (d, J=1.9 Hz, 1H), 8.52 (d, J=4.8 Hz, 2H), 7.01-6.87 (m, 3H), 5.17(ddt, J=8.7, 6.7, 3.4 Hz, 1H), 4.76-4.58 (m, 1H), 4.00-3.87 (m, 4H),3.40-3.27 (m, 4H), 2.43-2.22 (m, 4H), 2.05-1.87 (m, 2H), 1.86-1.71 (m,2H); ESMS (M+H⁺)=408.56.

Example 8N-[(cis)-4-[7-(3,6-dihydro-2H-pyran-4-yl)quinoxalin-5-yl]oxycyclohexyl]pyrimidin-2-amine(Compound 36)

As shown in step 8-i of Scheme 8, to a mixture of 7-bromoquinoxalin-5-ol(compound 1018, 200 mg, 0.89 mmol) and cesium carbonate (579 mg, 1.78mmol) in NMP (4.0 mL) was added(trans)-4-(pyrimidin-2-ylamino)cyclohexyl methanesulfonate (compound1014, 241.1 mg, 0.8887 mmol). The mixture was stirred for 18 hours at90° C., at which time an additional 0.5 eq of compound 1014 (241 mg,0.89 mmol) was added. After stirring at 90° C. for an additional 6hours, the reaction mixture was diluted with EtOAc, washed with H₂O,dried over Na₂SO₄, concentrated, and purified by medium pressure silicagel chromatography (0-5% MeOH/DCM) to provideN-((cis)-4-((7-bromoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(compound 1025): ¹H-NMR (300 MHz, CDCl₃) δ 9.01-8.77 (m, 2H), 8.29 (d,J=4.8 Hz, 2H), 7.89 (d, J=1.9 Hz, 1H), 7.25 (d, J=2.0 Hz, 1H), 6.53 (t,J=4.8 Hz, 1H), 5.43-5.22 (m, 1H), 4.79 (td, J=5.2, 2.5 Hz, 1H),4.18-3.95 (m, 1H), 3.51 (s, 1H), 2.22 (td, J=10.2, 9.6, 5.4 Hz, 2H),2.09-1.86 (m, 6H).

As shown in step 8-ii of Scheme 8, a mixture ofN-((cis)-4-((7-bromoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(compound 1025, 52 mg, 0.1299 mmol), Pd(dppf)Cl₂ (10.61 mg, 0.01299mmol),2-(3,6-dihydro-2H-pyran-4-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane(compound 1026, 27.3 mg, 0.13 mmol) , Na₂CO₃ (195 μL of 2M (aq)solution, 0.39 mmol) in DMF (1 mL) was flushed with nitrogen gas for 10minutes. The mixture was subjected to microwave radiation for 20 min at150° C. After cooling, the mixture was diluted with EtOAc, washed withH₂O, dried over Na₂SO₄, concentrated under reduced pressure and purifiedby medium pressure silica gel chromatography (0-5% MeOH/DCM) to provideN-[(cis)-4-[7-(3,6-dihydro-2H-pyran-4-yl)quinoxalin-5-yl]oxycyclohexyl]pyrimidin-2-amine(compound 36) as an off-white solid: ¹H-NMR (300 MHz, CDCl₃) δ 8.94-8.76(m, 2H), 8.29 (d, J=4.8 Hz, 2H), 7.67 (d, J=1.7 Hz, 1H), 6.53 (t, J=4.8Hz, 1H), 6.37 (tt, J=3.1, 1.5 Hz, 1H), 5.30 (d, J=7.9 Hz, 1H), 4.87 (dt,J=7.5, 3.6 Hz, 1H), 4.43 (q, J=2.8 Hz, 2H), 4.02 (t, J=5.5 Hz, 3H), 2.68(dqd, J=6.0, 3.4, 3.0, 1.8 Hz, 2H), 2.35-2.11 (m, 2H), 2.07-1.84 (m,6H); ESMS (M+H⁺)=404.2.

Example 9N-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(Compound 28)

As shown in step 9-i of Scheme 9, 7-bromoquinoxalin-5-ol (compound 1017,5.4 g, 24.0 mmol), 2-((trans)-4-hydroxycyclohexyl)isoindoline-1,3-dione(5.607 g, 22.86 mmol), and triphenylphosphine (8.994 g, 7.945 mL, 34.29mmol) were dissolved in anhydrous THF and the flask was cooled in an icebath. DIAD (6.93 g, 6.64 mL, 34.3 mmol) was added dropwise and thereaction was stirred at 0° C. for 5 minutes, then warmed to roomtemperature and stirred for 18 hours. The reaction mixture wasconcentrated under reduced pressure, the residue was treated with Et₂Oand stirred for 0.5 hour at RT, the precipitates filtered off, thefiltrate concentrated under reduced pressure, and the residue purifiedby medium pressure silica gel chromatography (0-50% EtOAc/hexanesgradient) to produce2-[(cis)-4-(7-bromoquinoxalin-5-yl)oxycyclohexyl]isoindoline-1,3-dione(compound 1028, 6.2 g, 60% yield): ¹H-NMR (300 MHz, CDCl₃) δ 8.95 (d,J=1.8 Hz, 1H), 8.86 (d, J=1.8 Hz, 1H), 7.91 (d, J=2.0 Hz, 1H), 7.88-7.80(m, 2H), 7.77-7.68 (m, 2H), 7.31 (d, J=2.0 Hz, 1H), 4.96 (t, J=2.9 Hz,1H), 4.29 (tt, J=12.5, 3.8 Hz, 1H), 2.88 (qd, J=12.9, 3.6 Hz, 2H),2.54-2.32 (m, 2H), 1.94-1.61 (m, 4H).

As shown in step 9-ii of Scheme 9, In a round bottom flask fitted with acondenser, a mixture of2-[4-(7-bromoquinoxalin-5-yl)oxycyclohexyl]isoindoline-1,3-dione (6.2 g,12.34 mmol), morpholine (1.61 g, 1.62 mL, 18.5 mmol) , and Cs₂CO₃ (12.06g, 37.0 mmol) in anhydrous toluene (73 mL) was treated with rac-BINAP(768.4 mg, 1.234 mmol) and Pd₂(dba)₃ (565 mg, 0.617 mmol). The reactionmixture was heated at 110° C. for 18 hours. After cooling to roomtemperature, the mixture was filtered through diatomaceous earth andconcentrated under reduced pressure. The residue was triturated withEt₂O and the solids collected by filtration and washed with Et₂O toproduce2-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)isoindoline-1,3-dione(compound 1029, 4.2 g) as yellow solid. The filterate was concentratedunder reduced pressure and purified by medium pressure silica gelchromatography (0-100% EtOAc/hexanes gradient) to produce an additional300 mg of compound 1029: ¹H-NMR (300 MHz, CDCl₃) δ 8.76-8.63 (m, 2H),7.85 (dd, J=5.4, 3.1 Hz, 2H), 7.79-7.60 (m, 2H), 7.09 (d, J=2.6 Hz, 1H),6.99 (d, J=2.5 Hz, 1H), 5.06 (t, J=2.8 Hz, 1H), 4.27 (tt, J=12.3, 3.8Hz, 1H), 4.02-3.85 (m, 4H), 3.49-3.27 (m, 4H), 3.03-2.75 (m, 2H), 2.37(d, J=14.0 Hz, 2H), 1.83-1.56 (m, 4H).

As shown in step 9-iii of Scheme 9, to a suspension of2-[(cis)-4-(7-morpholinoquinoxalin-5-yl)oxycyclohexyl]isoindoline-1,3-dione(2.3 g, 5.02 mmol) in MeOH (25 mL) was added hydrazine (321 mg, 315 μL,10.0 mmol) and the reaction mixture stirred for 18 hours at RT, overwhich time the initial suspension became homogenenous followed by theappearance of a precipitate. Et₂O (30 mL) was added and the reactionmixture stirred an additional 30 minutes. The precipitates were filteredoff, the filtrate concentrated under reduced pressure, the residuetreated with DCM (30 mL), and any remaining solids removed byfiltration. The filtrate was concentrated under reduced pressure toprovide (cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexanamine(compound 1030), which was used as is in subsequent reactions: ¹H-NMR(300 MHz, CDCl₃) δ 8.69 (d, J=1.9 Hz, 1H), 8.62 (d, J=1.9 Hz, 1H), 6.95(d, J=2.5 Hz, 1H), 6.90 (d, J=2.5 Hz, 1H), 5.00-4.67 (m, 3H), 4.03-3.81(m, 4H), 3.49 (s, 1H), 3.43-3.25 (m, 4H), 2.88 (q, J=6.2 Hz, 2H),2.36-1.96 (m, 6H).

As shown in step 9-iv of Scheme 9, to a solution so (cis)4-(7-morpholinoquinoxalin-5-yl)oxycyclohexanamine (415 mg, 1.264 mmol)and 2-methylsulfonylpyrimidine (400 mg, 2.53 mmol) was added DIEA (490mg, 661 μL, 3.79 mmol) and the reaction mixture was sealed in a vesseland heated to 100° C. for 16 hours. After this time, the volatiles wereremoved under a stream of nitrogen gas and the crude residue dissolvedin minimal amount of DCM. Purification by medium pressure silica gelchromatography (0-10% MeOH/DCM, 1% Et₃N] producedN-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-aminecontaining triethylamine hydrochloride as an impurity. Dissolved productin DCM and stirred with a silica-supported amine (Silabond amine® 40-63μm). The scavenger mixture was filtered, concentrated under reducedpressure, and dried under high vacuum to provideN-((cis)-4-((7-morpholinoquinoxalin-5-yl)oxy)cyclohexyl)pyrimidin-2-amine(Compound 28, 435 mg): ¹H-NMR (400 MHz, CDCl₃) δ 8.68 (d, J=1.9 Hz, 1H),8.61 (d, J=1.9 Hz, 1H), 8.27 (s, 1H), 8.26 (s, 1H), 6.94 (d, J=2.4 Hz,1H), 6.90 (d, J=2.4 Hz, 1H), 6.50 (t, J=4.8 Hz, 1H), 4.78 (s, 1H),4.08-3.97 (m, 1H), 3.94-3.86 (m, 4H), 3.37-3.28 (m, 4H), 2.20 (d, J=9.1Hz, 2H), 1.95-1.85 (m, 6H).

Example 10 Preparation ofN-[4-[7-(6-oxa-3-azabicyclo[3.1.1]heptan-3-yl)quinoxalin-5-yl]oxycyclohexyl]pyrimidin-2-amine(Compound 291)

To a mixture of 7-bromoquinoxalin-5-ol (47.53 g, 211.2 mmol),2-(4-hydroxycyclohexyl)isoindoline-1,3-dione (52.41 g, 213.7 mmol), andPPh3 (87.31 g, 332.9 mmol) in THF (740 mL) at 21° C. was addedtert-butyl (NZ)-N-tert-butoxycarbonyliminocarbamate (DTBAD) (79.51 g,328.0 mmol) in portions over 40 min so as to maintain the temperaturebelow 30° C. and the resultant reaction mixture was stirred at roomtemperature for a further 20 h.

The reaction was evaporated in vacuo. The residual reddish-brown viscousoil was dissolved in CH2Cl2 and filtered through a plug of silica in aglass column using applied air pressure (plug was made with 1L of drysilica suspended in CH2Cl2). The plug was eluted with CH2Cl2, thefractions were combined and evaporated in vacuo to afford a red-brownviscous oil/foam, that was then dissolved in 700 mL of MeOH beforeprecipitating. The mixture was stirred at room temperature for 1 h,filtered, washed with cold MeOH (500 mL) and Et2O (100 mL), then driedin vacuo to yield a tan solid that was suspended in 300 mL MeOH andbrought to reflux for 10 min. The suspension was cooled to roomtemperature and filtered, washed with a further MeOH and Et2O (4:1), anddried in vacuo to provide2-[4-(7-bromoquinoxalin-5-yl)oxycyclohexyl]isoindoline-1,3-dione (58.43g, 126.6 mmol, 59.94%). 1H NMR (400 MHz, CDCl3) δ 8.96 (d, J=1.8 Hz,1H), 8.86 (d, J=1.8 Hz, 1H), 7.91 (d, J=1.9 Hz, 1H), 7.89-7.82 (m, 2H),7.78-7.67 (m, 2H), 7.30 (d, J=1.9 Hz, 1H), 4.95 (s, 1H), 4.29 (tt,J=12.5, 3.7 Hz, 1H), 2.87 (qd, J=13.1, 3.5 Hz, 2H), 2.44 (d, J=15.2 Hz,2H), 1.80 (t, J=14.1 Hz, 2H), 1.67 (d, 2H). ESI-MS m/z calc. 451.05316,found 452.19 (M+1)+; Retention time: 0.92 minutes.

A mixture of2-[4-(7-bromoquinoxalin-5-yl)oxycyclohexyl]isoindoline-1,3-dione (1 g,2.211 mmol), 6-oxa-3-azabicyclo[3.1.1]heptane HCl (180 mg, 1.328 mmol),cesium carbonate (2.161 g, 6.633 mmol), Pd2(dba)3 (202.5 mg, 0.2211mmol) and rac-BINAP (275.3 mg, 0.4422 mmol) in dioxane (5 mL) wasstirred overnight at 70° C., then heated in a microwave reactor for 15min at 150° C. The reaction was then diluted with methylene chloride,filtered though Celite, and concentrated. Silica gel flash columnchromatography (0-5% MeOH/DCM) yielded2-[4-[7-(6-oxa-3-azabicyclo[3.1.1]heptan-3-yl)quinoxalin-5-yl]oxycyclohexyl]isoindoline-1,3-dione(750 mg, 72.1%) as a yellow solid that was carried on to the nextreaction.

To a solution of2-[4-[7-(6-oxa-3-azabicyclo[3.1.1]heptan-3-yl)quinoxalin-5-yl]oxycyclohexyl]isoindoline-1,3-dione(800 mg, 1.700 mmol) in EtOH (10 mL) was added hydrazine monohydrate(85.10 mg, 83.35 μL, 1.700 mmol) and the reaction was stirred at refluxovernight, then concentrated, diluted with DCM, and filtered. Thefiltrate was concentrated, and purified on a 40 g silica gel cartridgewith 0-50% (20% NH3/MeOH) to yield4-[7-(6-oxa-3-azabicyclo[3.1.1]heptan-3-yl)quinoxalin-5-yl]oxycyclohexanamine(450 mg, 77.8%) as a yellow solid. 1H NMR (300 MHz, Chloroform-d) ∂8.65(d, J=1.9 Hz, 1H), 8.53 (d, J=1.9 Hz, 1H), 6.83 (q, J=2.6 Hz, 2H), 4.83(t, J=6.0 Hz, 4H), 3.87-3.60 (m, 5H), 3.34 (dt, J=8.7, 6.6 Hz, 1H),3.01-2.83 (m, 1H), 2.23 (dq, J=11.3, 5.8, 4.8 Hz, 2H), 2.07 (d, J=8.7Hz, 1H), 1.92-1.62 (m, 6H).

A mixture of4-[7-(6-oxa-3-azabicyclo[3.1.1]heptan-3-yl)quinoxalin-5-yl]oxycyclohexanamine(190 mg, 0.5581 mmol), 2-fluoropyrimidine (60 mg, 0.6118 mmol) and DIEA(200 μL, 1.148 mmol) in 2-propanol (2 mL) was heated in a microwavereactor for 20 min at 150° C. The reaction mixture was concentrated, andthen purified from 12 g silica gel cartridge with 0-6% MeOH/DCM to yieldN-[4-[7-(6-oxa-3-azabicyclo[3.1.1]heptan-3-yl)quinoxalin-5-yl]oxycyclohexyl]pyrimidin-2-amine(120.2 mg, 48.9%) as a yellow solid. Mass+1: 419.23; Retention Time:0.72; NMR Annotation: 1H NMR (400 MHz, Chloroform-d) δ 8.42 (d, J=1.9Hz, 1H), 8.30 (d, J=1.9 Hz, 1H), 8.04 (d, J=4.8 Hz, 2H), 6.65-6.56 (m,2H), 6.28 (t, J=4.8 Hz, 1H), 4.99 (d, J=8.1 Hz, 1H), 4.60 (d, J=6.5 Hz,3H), 3.79 (dd, J=8.2, 4.0 Hz, 0H), 3.62-3.38 (m, 4H), 3.17-3.03 (m, 1H),2.07-1.90 (m, 2H), 1.89-1.59 (m, 7H).

Tables 1 and 2 provides analytical characterization data for certaincompounds of formula I (blank cells indicate that the test was notperformed).

Lengthy table referenced here US20210236505A1-20210805-T00001 Pleaserefer to the end of the specification for access instructions.

Lengthy table referenced here US20210236505A1-20210805-T00002 Pleaserefer to the end of the specification for access instructions.

Biological Assay of Compounds of the Invention Example 7 DNA-PKInhibition Assay

Compounds were screened for their ability to inhibit DNA-PK kinase usinga standard radiometric assay. Briefly, in this kinase assay the transferof the terminal ³³P-phosphate in ³³P-ATP to a peptide substrate isinterrogated. The assay was carried out in 384-well plates to a finalvolume of 50 μL per well containing approximately 6 nM DNA-PK, 50 mMHEPES (pH 7.5), 10 mM MgCl₂, 25 mM NaCl, 0.01% BSA, 1 mM DTT, 10 μg/mLsheared double-stranded DNA (obtained from Sigma), 0.8 mg/mL DNA-PKpeptide(Glu-Pro-Pro-Leu-Ser-Gln-Glu-Ala-Phe-Ala-Asp-Leu-Trp-Lys-Lys-Lys,obtained from American Peptide), and 100 μM ATP. Accordingly, compoundsof the invention were dissolved in DMSO to make 10 mM initial stocksolutions. Serial dilutions in DMSO were then made to obtain the finalsolutions for the assay. A 0.75 μL aliquot of DMSO or inhibitor in DMSOwas added to each well, followed by the addition of ATP substratesolution containing ³³P-ATP (obtained from Perkin Elmer). The reactionwas started by the addition of DNA-PK, peptide and ds-DNA. After 45 min,the reaction was quenched with 25 μL of 5% phosphoric acid. The reactionmixture was transferred to MultiScreen HTS 384-well PH plates (obtainedfrom Millipore), allowed to bind for one hour, and washed three timeswith 1% phosphoric acid. Following the addition of 50 μL of Ultima Gold™high efficiency scintillant (obtained from Perkin Elmer), the sampleswere counted in a Packard TopCount NXT Microplate Scintillation andLuminescence Counter (Packard BioScience). The K_(i) values werecalculated using Microsoft Excel Solver macros to fit the data to thekinetic model for competitive tight-binding inhibition.

Each of compounds 1-291, 295-331, 333-367, 369-523, 525-640, 642-644,646, and 648-659 has a K_(i) of less than 1.0 micromolar for theinhibition of DNA-PK. Each of compounds 3, 6-14, 16-18, 23-34, 36-37,39-41, 43-46, 49-72, 74-76, 78, 84-101, 103-123, 127-200, 202-291,295-299, 305, 307-331, 333-341, 343, 347-366, 369-374, 376-391, 393-519,521-523, 526-554, 556-610, 612-640, 642-644, 646, 648-655 and 657-659has a K_(i) of less than 0.10 micromolar for the inhibition of DNA-PK.

Although the foregoing invention has been described in some detail byway of illustration and example for purposes of clarity ofunderstanding, it will be readily apparent to those of ordinary skill inthe art in light of the teachings of this invention that certain changesand modifications may be made thereto without departing from the spiritor scope of the appended claims.

LENGTHY TABLES The patent application contains a lengthy table section.A copy of the table is available in electronic form from the USPTO website(https://seqdata.uspto.gov/?pageRequest=docDetail&DocID=US20210236505A1).An electronic copy of the table will also be available from the USPTOupon request and payment of the fee set forth in 37 CFR 1.19(b)(3).

1. A compound of Formula (I):

or a pharmaceutically acceptable salt thereof, wherein: Ring A is

Ring B is

 wherein Ring B is optionally substituted with up to 4 fluorine atoms,up to two OH, or up to two C₁₋₄alkyl, which is optionally substitutedwith up to 3 fluorine atoms, up to two OH, or up to two —OC₁₋₂alkylgroups; Ring C is a cyclohexane or a cyclobutane ring; X is —NH—, —O—,or —OC₁₋₄ alkyl-; each of R¹ and R² is, independently, hydrogen,—C(O)NHR⁴, —C(O)OR⁴, —NHC(O)R⁴, —NHC(O)OR⁴, —NHC(O)NHR⁴, —NHS(O)₂R⁴,—C₀₋₄ alkyl-NHR⁴, or —OR⁴, wherein R¹ and R² cannot simultaneously behydrogen, and wherein R¹ and R² and the intervening carbon atom can forma dioxane or dioxolane ring; R³ is hydrogen, —C₁₋₄alkyl, fluoro, chloro,—OC₁₋₂alkyl, —C(O)H, —C(O)OH, —C(O)OC₁₋₂alkyl, —CN, —C(O)NHC₁₋₂alkyl, or—C(O)NH₂, wherein each of said R³ alkyl is optionally substituted withup to 3 fluorine atoms, up to two OH, or up to two OC₁₋₂alkyl groups; R⁴is hydrogen, C₁₋₄alkyl, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₅cycloalkyl,phenyl, a 5-10-membered monocyclic or bicyclic heteroaryl ring selectedfrom pyrrole, imidazole, pyrazole, triazole, thiazole, isothiazole,oxazole, pyridine, pyrimidine, pyrimidinone, pyrazine, pyridazine, andquinoline, or a 4-10-membered monocyclic or bicyclic heterocyclyl ringselected from oxetane, tetrahydrofuran, tetrahydropyran,dihydroisoxazole, pyrimidine-2,4(1H,3H)-dione, dihydrofuropyrimidine,dihydropyranopyrimidine, dihydropyrrolopyrimidine, tetrahydropteridine,and tetrahydropyridopyrimidine, wherein each of said R⁴ groups isoptionally substituted with up to four Br, Cl, F, or C₁₋₄alkyl, up tothree CN, NO₂, C₂₋₄alkenyl, C₂₋₄alkynyl, C₃₋₆cycloalkyl, C₀₋₄ alkyl-C₃₋₅cycloalkyl, C₀₋₄ alkyl-O—C₁₋₄ alkyl, C₀₋₄ alkyl-O—C₀₋₄ alkyl-C₃₋₅cycloalkyl, C(O)OC₁₋₄ alkyl, C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl, C₀₋₄alkyl-C(O)NH₂, C(O)NHC₁₋₄ alkyl, C(O)N(C₁₋₄alkyl)₂,C(O)NH(C₀₋₄alkyl-C₃₋₅ cycloalkyl), CH₂OR⁵, C₀₋₄ alkyl-C(O)R⁵, C₀₋₄alkyl-C(O)N(R⁵)₂, C₀₋₄ alkyl—C(O)OR⁵, C₀₋₄ alkyl-NHC(O)R⁵, C₀₋₄alkyl-N(R⁵)₂, a heterocyclic ring system selected from oxetane,azetidine, tetrahydrofuran, dihydropyran, tetrahydropyran, morpholine,piperidine, pyrrolidine and piperazine, a heteroaryl ring systemselected from furan, oxazole, oxadiazole, pyrrole, pyrazole, triazole,oxadiazole and tetrazole, or up to two OR⁵, wherein each of saidoptional R⁴ substituents is optionally substituted with up to fourfluorine atoms, up to two C₁₋₄alkyl groups, up to two OH groups, up totwo OC₁₋₄alkyl groups, up to two SC₁₋₄alkyl groups, a C(O)C₁₋₄ alkyl, aC(O)OC₁₋₄ alkyl, or a C(O)OC₀₋₄ alkyl-C₃₋₅ cycloalkyl; and each R⁵ is,independently, hydrogen, C₁₋₄alkyl, a 5-6-membered heteroaryl selectedfrom imidazole, triazole, thiazole, pyridine, and pyrimidine, or a4-6-membered heterocyclyl selected from oxetane, tetrahydrofuran, andtetrahydropyran, and each R⁵ group is optionally substituted withchloro, up to three fluorine atoms, up to two C¹⁻²alkyl, CH₂OH, CN, upto two OH, up to two OC₁₋₂alkyl, a spirooxetane, pyrrolidine, ortriazole, or two R⁵ groups together with the intervening nitrogen atomform a morpholine ring, azetidine ring, pyrrolidine ring, piperidinering, or piperazine ring.
 2. The compound of claim 1, or apharmaceutically acceptable salt thereof, wherein Ring C is cyclobutane.3. The compound of claim 2, wherein the compound is of Formula (II):

or a pharmaceutically acceptable salt thereof. 4-9. (canceled)
 10. Thecompound of claim 2, or a pharmaceutically acceptable salt thereof,wherein X is —O— or —OC₁₋₄ alkyl-.
 11. The compound of claim 2, or apharmaceutically acceptable salt thereof, wherein

12-16. (canceled)
 17. The compound of claim 1, or a pharmaceuticallyacceptable salt thereof, wherein Ring C is cyclohexane.
 18. The compoundof claim 17, wherein the compound is of Formula (III):

or a pharmaceutically acceptable salt thereof.
 19. The compound of claim18, or a pharmaceutically acceptable salt thereof, wherein X is —NH—.20. The compound of claim 17, wherein the compound is of Formula(III-A):

or a pharmaceutically acceptable salt thereof.
 21. (canceled)
 22. Thecompound of claim 20, or a pharmaceutically acceptable salt thereof,wherein R² is —C₀₋₄ alkyl-NHR⁴ or —OR⁴. 23-24. (canceled)
 25. Thecompound of claim 17, wherein the compound is of Formula (III-B):

or a pharmaceutically acceptable salt thereof.
 26. (canceled)
 27. Thecompound of claim 25, or a pharmaceutically acceptable salt thereof,wherein R¹ is —C₀₋₄ alkyl-NHR⁴ or —OR⁴. 28-29. (canceled)
 30. Thecompound of claim 17, or a pharmaceutically acceptable salt thereof,wherein


31. (canceled)
 32. The compound of claim 18, or a pharmaceuticallyacceptable salt thereof, wherein X is —O—.
 33. The compound of claim 17,wherein the compound is of Formula (III-C):

or a pharmaceutically acceptable salt thereof. 34-37. (canceled)
 38. Thecompound of claim 17, wherein the compound is of Formula (III-D):

or a pharmaceutically acceptable salt thereof.
 39. (canceled)
 40. Thecompound of claim 38, or a pharmaceutically acceptable salt thereof,wherein R¹ is —C₀₋₄ alkyl-NHR⁴ or —OR⁴. 41-43. (canceled)
 44. Thecompound of claim 32, or a pharmaceutically acceptable salt thereof,wherein

45-60. (canceled)
 61. A pharmaceutical composition comprising a compoundof claim 1, or a pharmaceutically acceptable salt thereof, and apharmaceutically acceptable excipient. 62-63. (canceled)
 64. A method oftreating cancer or inhibiting cancer cell growth in a patient comprisingadministering to said patient an effective amount of the compound ofclaim 1, or a pharmaceutically acceptable salt thereof, or apharmaceutical composition comprising said compound or pharmaceuticallyacceptable salt thereof, either alone or in combination with one or moreadditional therapeutic agent.